Karl couldn't leave Cousins in for another minute to close the 3rd? Play him 42+ minutes if you have to. Gotta win games, unless you're alright with a 2-8 record.
He was barely making it up the court. And let's not forget he's coming of a sore Achilles.
21 points in 1 quarter? 45 more seconds isn't going to kill you, sore achilles or not. If something as serious as an achilles is truly a problem, you shouldn't be playing starting minutes in the first place, which he has been logging.