There's a fine line between being self confident and arrogant Jake. We learn more from mistakes than success, as long as you acknowledge those mistakes. Arrogant pricks that behave like they are never wrong are a disaster waiting to happen - just look at most of our politicians, of all persuasions.
Perhaps you could argue that he should not have made those thoughts public, but if you follow what Hardwick has said about modern players questioning why certain decisions are being made and that he is happy for this to happen and to explain to them the reasons, it seems that for him to criticise the players performance but not put put his hand up for his own shortcomings would go against the grain.
My feeling is the players would respect Dimma for this, I know I do.