Guy drops a zero day on a major service provider, guy gets his account suspended (temporarily, it turns out). In what possible world is disabling an account that has recently exploited your live product in a very visible way not ok? Remember, you don't have a chance to call a meeting with the C level guys and your community manager - you're one or two guys responding on a weekend.
The rest of the "oh my god the sky is falling" drivel about how terrible a bug it could have been and how they should never have had such a vulnerable bug in the first place is even worse. Security bugs are fuckups by nature - nobody sat and said well shit I was going to code this wrong but since it might allow a lot of access I won't. In terms of OH SHIT bugs this is actually rather small - I'm sure github's live infrastructure has been open to lower level remote execution vulnerabilities over the years - newsflash: we all have been. Getting user or superuser or db admin is going to almost certainly be a lot worse than an application authentication level vulnerability.
You say none of that matters because it's such an obvious bug and people have known not to do that kind of thing for years? Say hello to our old friends "buffer overflow" & "use after free" - still grabbing msft aapl & goog after all these years.
TL;DR - stop acting like children.