I don't really see a problem with what he said, and I don't get why anyone really would either. He's pretty much right.
I'd rather have a guy who thinks like this and goes out and gets the job done(like he did for all of last season, with presumably the same mindset he just showed) than someone who is going to freak the f*** out over an outing like this and dwell on it and carry it out to the mound with him next time. Like he said, it was ONE series. That's it. He has plenty more of them to turn it around.
The only time I would be bothered by statements like this is if they are coming from the manager or something.