$15k and a likely open FB job offer
Really? For brute forcing an un-rate-limited endpoint? I doubt it.
But you're right, he might have just got lucky. The one fish in a school of 100,000 who finds the hole in the net probably isn't smarter than all the other fish. But that just strengthens the argument that companies should reward very generously for these exploits, because increasing the number of white-hats looking for them is a good way to ensure that they get found by one.
https://hackerone.com/anand786 https://www.facebook.com/whitehat/thanks (listed 2015, 2014, 2013)