This isn't all that complicated, as far as I can tell.
Guy discloses a vulnerability. He knows it potentially has wide reaching security concerns, and downloads enough data to prove that if necessary.
Guy gets shortchanged on the bounty, indicating that either a) facebook is trying to shortchange him, or b) facebook doesn't realize how big of a vulnerability this truly is
Everything about Facebook's response indicates b): they didn't realize how big a vulnerability this truly was. Otherwise, the data he downloaded would have been useless by the time he used it.
You can argue that the guy "went rogue" by hostaging information, but fact is he deserved to be paid more and he was able to prove it. Now facebook looks bad.
Guy discloses a vulnerability. He knows it potentially has wide reaching security concerns, and downloads enough data to prove that if necessary.
Guy gets shortchanged on the bounty, indicating that either a) facebook is trying to shortchange him, or b) facebook doesn't realize how big of a vulnerability this truly is
Everything about Facebook's response indicates b): they didn't realize how big a vulnerability this truly was. Otherwise, the data he downloaded would have been useless by the time he used it.
You can argue that the guy "went rogue" by hostaging information, but fact is he deserved to be paid more and he was able to prove it. Now facebook looks bad.