Earlier quoted context omitted.
You're conflating two issues here. He's arguing that the Rails team was ignoring an important issue by noting it was an easy end-user fix, and GitHub overreacted by suspending him after he tried several times to bring it to their attention, and then grossly mislead their user base as to the extent of the issue (which sounds like a really fundamental security issue that any professional Rails developer should know how…
Did he notify github directly, or did he notify the rails team in a github-issue in the rails project? If he didn't actually contact github directly and just assumed they would see the rails issue on a weekend, then I wouldn't exactly call it 'notice'. If he did submit it to github via the proper channels before taking action, and nothing was done within a reasonable timeframe (eg. not just an hour or two on a sunday…
https://github.com/blog/1068-public-key-security-vulnerabili...