I don't know the source of the quote and am trying to find it. But I think the person meant either. It won't be like a government crack down or a larger scale force... it'll be like you suggested an event initiated by a person or small group of people that tank the whole thing via a bug or nefarious actions.

SatoshisSkeleton

bitcoin

"Bitcoiners are the likeliest thing to break Bitcoin"... what do you think?

Do you mean the most likely thing to break bitcoin is a bug introduced by the programmers?  Or do you mean malicious action by network participants?  (or both?  A design flaw that enables malicious action)