Corrected entry: In the cabin Jeremy Renner looks up and sees the name Jason Bourne carved into the wood. Jason Bourne was one of the many aliases of David Webb - he wasn't given the name Jason Bourne until he completed his training.
Phixius
25th Jan 2015
Correction: Aaron (Renner) is in this cabin during a disciplinary exercise, not a training exercise; his "training period" has been long since completed. It's possible, even likely, that David returned to this cabin for same or similar reasons after having already been assigned the alias of Jason Bourne.
Phixius ★