A cursory examination of the claims suggests several problems with the story, leading some to question Titor's claims and label him a fraud or a hoaxer.
For instance, he describes a future in which money is largely dispensed with in favor of communal bartering, but in other cases claims that money is widely used and they still have credit cards. These claims appear to be opposed, it does not seem obvious how one could operate a credit system with widespread barter because of the smaller number of cash transactions this would imply. In another post he speculated that today's money would be usable in his time, but this would be after the collapse of the federal government according to his own history, which would make the money worthless.[2]
Of particular interest is the fact that the device is implied to be a Tipler Cylinder, but one well known "side effect" of this device is that it can only be used to travel to times in which the device already existed – Titor could travel into the past with one, but only to 2034, which is when he claimed it was first built.[3] It has been suggested that the description of the system has been copied with almost no modification from a particular work, the general science book Hyperspace written by Dr. Michio Kaku.[4]
The images posted by Titor are likewise problematic. The image of the laser pointer's beam being "bent" has the obvious problem that objects around the beam are not bent. For instance the framing of the window visible in the background shows no distortion, which would not be the case if there was a large gravity gradient in the area. Some have speculated the "beam" is a fiber optic.[5]
Titor claimed that he was sent back to obtain an IBM 5100 because it could emulate mainframes. Supporters have implied that this capability was a "secret" that was not known in 2000/1 when the posts were being made. However, this capability was actually widely known in the industry, and commented on in depth in numerous publications, both about the 5100 and APL in general.[6] References to this fact were also available on the internet as early as 1999. This is a fairly obscure bit of trivia, however, which suggests whoever was making the posts was familiar with the machine, or had an interest in retrocomputing.[7]
Other predictions have simply proven not to be true. For instance, he stated that the Olympics Games would end with the 2004 Summer Olympics, but this proved contrary to subsequent real-world events as the 2006 Winter Olympics were successfully held.
In light of such predictive failings supporters have speculated, ex post facto, that the history relayed by Titor could have referred to one possible course for the future, suggesting that humans may have since created an alternate future by going about things differently. Of course, any statement could be explained away in this fashion. This is precisely the sort of "unfalsifiable" claim that Karl Popper was referring to when he developed his thoughts on falsifiability; when faced with evidence that contradicts a claim, that claim is simply modified or removed outright to fix the problem. There is no limit to the modifications that could be carried out, thereby rendering it impossible to state that the facts disagree with the claims. For instance, if every one of the original claims turns out to be wrong, it could simply be stated that "Titor did his job". This is, as Popper pointed out, a key indication of a pseudoscience.