Completely agree with the OP. I've lost all respect for Kiefer.
Kiefer was not throwing his racquet at Grosjean, but it was a stupid thing to do. The thrown racquet was a hinderance -- nothing to do with whether it happened just before Grosjean hit the ball or just after -- and to not concede the point or suggest a play-over was cheap, cheap, cheap.
And to cap it off, that perfunctory handshake at the end. Not only is he a head case, he's a cheater, low-rent, mutt head case.
I hope his next opponent creams him.