Without witnesses to the act or video it will be tough to verify.
At the World Record GB back in the 1990's it was only one woman
Annabel Chong on the stage of a movie set. In that one, you were doing her in groups of 5 and you were being filmed. You only had 5 to 10 minutes with her until they called the next group up. Most everyone got to have at least 3 rounds with her because not everyone showed up that signed up for the event. She wound up being with just under 70 guys and performed a little over 250 sex acts.
When she was asked what the hardest/worst part of it was (I still remember what she said. Lulz) her reply was, "The fingernails of the guys scratching me when they were fingering me."
At least in this one the you are required to cum and you get a private room. If they don't have fluffers on site (I saw nothing about them on the LP or in the details.) I think it would be tough to get off in JUST 15 minutes.
I also find it VERY HARD to believe that this is NOT going to be recorded. How are they going to verify this? Do a sweep of the room after each guy and collect their jizz filled condoms as they come out of the room so they can count them all up at the end?! Lulz
I don't think that, "We had 2,500 guys who went through the doors and came out.", would be enough evidence to prove they had intercourse/sex acts and came as well. (Then again, this is really just some BUZZ/HYPE marketing so it probably doesn't matter.)
If the guys took the entire 15 minutes they could only have 288 guys between 3 women in 24 hours. On the other hand, if the guys all only took 1 minute to cum they could have 4,320 guys!!