I’m far from a Bernie Bro but this is revisionist history. Hillary did the same thing to Obama in 08. Matter of fact Hillary stated she was going to stay in the race even after it was clear Obama was going to win the nomination. She said you never know what can happen, and mentioned RFK getting assassinated.
Clinton: RFK assassination reference unrelated to Obama - CNN.com
Bernie endorses her at the convention and campaigned for her. Bernie is not the reason HRC lost to Trump. Also she said “ I hope he endorse whoever get the nomination” like he has zero percent chance of winning. While I don’t think Bernie should be the favorite, he still have a decent shot at winning. Statements like this is not helpful, and it only going make his supporters dig in harder.