Jim Hoffman suddently appeared on the scene of the 9/11 truth movement in 2003 as a full MIHOPer. He advocated CD at the WTC, no AA77 at the Pentagon, and that the hijackers were fake, and therefore the cell phone calls were fake. He gained credibility by claiming to use his scientific background to examine the evidence for CD and began writing reports and presenting evidence of CD, including discussing the surprisingly small size of particles and level of pulverization of the debris of the WTC. None of it was original research, but seemed to merely plagerize what other researchers, such as Jeff King, had already reported.

After establishing his credibility and standing in the movement with the CD research and advocacy, he then suddenly did a back flip in 2004 and became almost a LIHOPer advocate, in that he bagan to support the possibility that there really could have been muslim hijackers involved, at least in the WTC attack and UA93, if not the Pentagon attack (since it was obvious that Hani Hanjour could not have been at the controls). So, he suddenly became a supporter of the OCT of the AA77 crash at the Pentagon and shifted from a skeptic to a supporter of the OCT of at least most of the cell phone calls, except for the 2 that were the most ridiculous:

Jim Hoffman of 9/11 Research, 9/5/2003:
"Pentagon Attack
The damage to the Pentagon is inconsistent with the impact of a large jetliner.
Evidence
No public evidence shows a 757 approaching the Pentagon, nor remains of such an aircraft.
There are no photographs showing a 757 approaching the Pentagon. 5 security camera photos released in 2002 do not show anything like a 757, but do show a vapor trail like that of a missile.
Video recordings from adjacent businesses were seized by the FBI shortly after the attack and never seen since.
The lawn of the Pentagon outside the west wall was free of aircraft parts identifiable as belonging to a 757. The few small scraps photographed look like they belonged to a much smaller aircraft such as a Global Hawk."
Aircraft Remains
As the photographs immediately following the attack show, the punctures in the west wall of the Pentagon were far smaller than the profile of a Boeing 757-200, and the lawn was nearly immaculate, free of any large aircraft debris. The few scraps that appear in some photographs are far too thin and light to be part of such an aircraft. Photographs show curious activities by apparent Pentagon employees at the crash site before the arrival of rescue and recovery workers. Much of this evidence is presented and analyzed in the documentary Painful Deceptions. A video taken from a helicopter shows a row of dozens of men in white shirts and ties walking across the lawn in front of the crash site, looking at the ground as if to scour the grass for any telltale evidence. A photo shows about a dozen similarly dressed individuals carrying away a large crate covered with a tarp. Another shows a few such men carrying away small pieces of wreckage. This was all happening around the time firefighters were arriving on the scene. "

Jim Hoffman of 9/11 Research, 6/12/2007:
"But wasn't the damage to the Pentagon's facade inconsistent with the crash of a jetliner the size of a Boeing 757?
No. Contrary to misleading descriptions popularized by popular books and videos, damage to the facade included punctures extending about 100 feet in width on the first floor and about 18 feet on the second floor. Damage on either side of the impact punctures extends about as far as the profile of a 757's wings. Lacking an example of a closely comparable crash, claims that the Pentagon's crash damage is inconsistent with the impact of a 757 lack scientific merit.
But don't photographs immediately after the attack show that there was no plane wreckage?
No. First, since most pre-collapse photographs were taken from the highway -- more than 500 feet away from the crash site -- they fail to show debris fields near the building. Second, the impact punctures were large enough to allow vast majority of the plane's mass to enter the Pentagon. Third, other crash examples show that such a high-speed crash could be expected to shred the aircraft into small, mostly unrecognizable debris. "

Jim Hoffman of 9/11 Research, 9/5/2003:
"The Many Oddities of the Alleged Calls From Doomed Flights
There are a number of oddities about the alleged cell phone calls from the people on the doomed flights. Here are just a few.
The calls have a peculiar distribution with thirteen calls attributed to Flight 93 passengers, but only zero to one attributed to passengers on any of the other flights. Why would the hijackers be so permissive on that flight but only selectively permissive on others, letting Flight 11 Attendant Madeline Sweeney talk for the entire hijacked portion of its route?
Several calls have the ring of fakery. They include the following:
The call to Mark Bingham's mother, Alice, from someone claiming to be her son, was very short. After his awkward introduction, the caller failed to respond to Alice's twice-repeated question, and then the line went dead.
In one of the calls attributed to Barbara Olsen, the caller asked Ted Olsen "What should I tell the pilot?", referring to Chic Burlingame, the captain, who was then supposedly seated in the rear with Barbara. Chic was a graduate of Naval Academy and flew F-4s in Vietnam. It seems highly doubtful that he could have been persuaded to hand over the stick without a fight, and agree to sit in the back of the plane, especially when controllers had been broadcasting to pilots that Flight 11 had been hijacked.
There is no public evidence of recordings of any of the conversations, despite the extended length of some of them, except for Madeline Sweeney's alleged call.
Sweeney, who was the "anchor" for Flight 11, says: "I see, buildings, water, ... Oh my God!", immediately before the crash, as though she, a Massachusetts-based flight attendant of 12 years, had never seen the Manhattan skyline before. Supposedly she was continuously monitoring the view out a window.
A person claiming to be Todd Beamer, one of the heroes of the purported Flight 93 passenger revolt, talked to a Verizon supervisor for 13 minutes. Why would Beamer prefer to talk to a stranger than to someone in his own family?
The alleged Todd Beamer talked like a reporter, giving the blow-by-blow account of the goings-on right up to the famous "Let's roll".
Except for the Beamer call, all of the Flight 93 calls were very short, usually just a few sentences, with the caller ending the conversation by saying they had to go, only to call back later in many cases for another short call. Why did they have to go? Were the hijackers enforcing a one-minute time limit on all conversations?
Canadian scientist A.K. Dewdney concludes in the article Ghostriders in the Sky that cellphone calls could not be made reliably if at all from Flight 93.
He conducted experiments with cell phones to show that cell phones seldom work above 10,000 feet. Several of the alleged Flight 93 calls were made when the plane would still have been near its cruising altitude of 35,000 feet.
Below 10,000 feet, according to Dewdney, cell phone calls made from a jet would cause problematic "cascades" in networks of cellsites on the ground. Cascading is caused by a phone at several thousand feet of elevation being unable to distinguish which of several cellsites has the strongest signal. This causes the phone to repeatedly select a new channel and try again, possibly leading to a network-wide breakdown. No such cascades were reported on September 11th."

Jim Hoffman of 9/11 Research, 6/13/2007:
"Contrary to Dewdney's findings, we have received reports that cell phones do work from aircraft. Other evidence that cell phone calls are possible from jetliners in flight comes from a study by Carnegie Mellon researchers that monitored spectrum frequencies generated by cell phone transmissions during commercial passenger flights. They found that an average of one to four cell phone calls are made during a typical flight. 1 Furthermore, most of the calls from Flight 93 were apparently made from airphones, not cell phones, with the few cell phone calls apparently happening late in the flight when the jetliner's altitude was low.
Although arguments for the majority of calls being faked don't hold up to scrutiny, the reported content of two of the calls raises questions.
In one of two calls Ted Olsen said he received from his wife on Flight 77, she reportedly asked "What should I tell the pilot?," referring to Chic Burlingame, the captain, who was then supposedly seated in the rear with Barbara. Burlingame was a graduate of Naval Academy and flew F-4s in Vietnam. How could Burlingame have been persuaded to hand over the stick without and agree to sit in the back of the plane -- especially when controllers had been broadcasting to pilots that Flight 11 had been hijacked?
Madeline Sweeney, who called to her supervisor from Flight 11, reportedly stated: "I see, buildings, water, ... Oh my God!", immediately before the crash. Why would Sweeney -- a Massachusetts-based flight attendant of 12 years -- speak as though had never seen the Manhattan skyline before?"

Since his back flip, Hoffman has consistently utilized debunking and disinformation type arguments against his detractors, including calling theories that dispute parts of the OCT that he supports a Hoax - probably the most common smear that propagandists use against people who try to expose criminal conspiracies of the military/government. Too often Jim Hoffman utilized ad hominem and other false arguments against his opponents rather than evidence-based arguments, particularly in regard to the Pentagon Attack, and when he does address evidence, he often distorts the facts about evidence and makes unsupported claims. One of his most recent blatant smear-type hit pieces is this one:

http://911research.wtc7.net/essays/pentacon/index.html

Google Earth Exposes
Pentagon Flyover Farce
or
Critiquing PentaCon
(Smoking Crack Version) *
by Jim Hoffman

Version 1.0, July 26, 2009

"Smoking Crack Version" is a parody of CIT's "Smoking Gun Version" subtitle. I find it hard to believe that a genuine 9/11 researcher/activist would use this kind of childish over-the-top ad hominem attack against other researchers in the movement it he/she didn't have an agenda to demonize and smear their opponents rather than wanting to use scientific or respectable methods to debate and discuss the issues to search for the truth.

Hoffman's rebuttal to the Popular Mechanics hit piece against the 9/11 truth movement on the surface seemed to be helping the truth movement, but to me it appeared to be more like a trojan horse smear against almost all other legitimate questions beyond WTC CD evidence, in which Hoffman agreed with most of the attacks that Popular Mechanics made against the questions/evidence for MIHOP type conspiracy of 9/11, even beyond the obvious blatant disinfo regarding space beams, pods, no planes at the WTC, etc.