Let's not all blow this out of proportion. Kimbrel hasn't lost in almost a month and hasn't blown a save since May 28th. Everyone has a couple bad appearances a season, and he has had many, many solid appearances this year. It sucks that one of his bad ones was against the Yankees, but in the end, this game had little meaning now that the Sox have clinched.
A brief scan of his BR page will tell you all you need to know: He has helped the Red Sox in far more of his appearances than he has hurt them. Far, far more. And that's basically what you need from a bullpen guy. Anyone holding out for season-long ERAs of 0.00 and 100% converted save opportunities is going to be disappointed. If this meltdown had happened in the middle of May, far less people would probably be acting like this was the end of the Sox's chances for ever winning a game ever again. Just relax.
Besides, we are all ignoring the real issue here. The blame for tonight rests on the shoulders of UN? for starting the Gamethread, obviously.