I'm actually an MS3 at UTSW and just took step a few months ago. This person looks like they are in the same class as me (2012). Not many people want to do NSG so I could probably figure out who the person is 😀. This writeup is just an anecdotal story from 1 student on our wiki, but I will admit that his/her study plan is very similar to the study method virtually all of my friends at the school used.
I am also in the 4th quarter after the first 2 years at UTSW and ended up with a 247 with a very similar study plan (only no DIT, and I didn't use FA during MS2 - more emphasis on spamming UWORLD). FAx4, UWORLD complete bank x2, Goljian audio x1 using the 127 page annotated notes mainly. Went from literally a failing score on NBME1 to 247 on the real thing in 29 days.
I think the reason you can make such a massive jump in such a short period is the fact that people hemorrhage so much information over the course of the first 2 years. So just because someone does well on an exam that happened a year ago doesn't mean they really remember that much more than you a month out from step. Being in the 4th quartile can hurt your ego, but don't ever sell yourself short.