The key problem is that the study relies on retrospective, self-reported data. There is no way to actually know one's actual level of surprise at the time that they heard the news.  Even when someone is currently surprised, it is difficult to measure the level of emotion that they are experiencing. But asking someone to recall their level of surprise 14 years after the assassinations, that is not very precise data gathering.  The second problem is that we have to assume that their memories are actually accurate.  Brown and Kulik appear to trust that the participants' ability to recall a lot of detail was evidence of flashbulb memories, but later research - for example, Neisser and Harsch, showed that these memories were not reliable - in spite of the fact that the participants were highly confident of their memories.

The importance drive model goes further than the original theory that proposed that surprise is responsible for the creation of flashbulb memories. The theory argues that it is personal relevance that makes the memory different. This is especially true when the event is life-threatening.

Because the participants were asked where they were when the president was killed, they may have "come up with" a response so as to not appear to be unpatriotic.

Phelps found that those that were closer to Ground Zero had more activity in the amgydala, indicating that the nature of the memory and its retrieval was different from those that were further away on the day of the attack.

An artifact is when something shows up in a brain scan that is the result of the fMRI itself.  As the amgydala was activated, it is possible that this was the result of anxiety while in the fMRI, rather than because of memory retrieval.  However, the researchers took a baseline measure of activity in the amygdala to control for this.

de Quervain's study appears to indicate that there are genetic roots to Flashbulb memories. Those that have a variation of the α2b-adrenoceptor were more likely to have flashbulb memories.

Kulkoffsky has found that collectivistic cultures have fewer personalized flashbulb memories than individualistic cultures. In the case that the memory is based on a national tragedy, the rate of FBMs was the same.