I see no reason to not believe him. I think the test is mostly reading comprehension anyhow, on the assumption that you have the requisite understanding, which isn't that much. Programmers think iteratively, and that's the sort of mentality that's always helped me through standardized tests. I imagine if he were to fake the results, he would have given himself higher scores in verbal reasoning and writing. My question is which of the four requisite courses had he taken in college, and what classes did he take in HS? I think that you also have to recognize that not everyone takes the expensive courses he's talking about, or done the in-depth studying to which he alludes. Firstly, about half of all test-takers take the MCAT twice. People on SDN generally take their pre-med experience very seriously, but I think there's a huge crowd of people beyong SDN who don't do any studying for the MCAT. I can also say that I honestly wouldn't be surprised if some people deliberately tank the MCAT because their parents are pushing them into medicine, and they don't want to go to med school--it would be the single easiest way to get out of it. Finally, having nothing to lose makes test taking easier. The dude had no stress at all, and no struggles with second-guessing himself, and above all, that would have given him plenty of time to finish the test.
I think fear is the mind-killer.