There is no such thing as good criticism after a match.
I always try to say encouraging words to my partner after the match but I’ve heard many a player come down the court after a match and start telling his partner all the things he did wrong, end of relationship.
You just can’t do that because you probably took some shots your partner didn’t agree with either.
One thing that does happen is you take the winning edge away from your partner because the next time he may not take what could be the winning shot for fear of criticism and you’ll be going home again!