I ran the marathon at this race many years ago. It's very hilly, and starts at 6 or 7 p.m. and is always super hot. The out and back section would be really easy to just turn around early on in the dark, as it wasn't manned (at least not back then) I'm only skeptical because the course record for the marathon used to be held by 2:17 marathoner who ran 3:07 or something at the Boogie. The race is not a record breaking kind of course.
Benov’s manually entered the 50 on Strava without gps so no way to be certain. He used gps two days earlier for a 4 mile run on the out and back section though which shows the amount of elevation on it (313ft).
So you are on strava but you don't post your best performance?