It was a poor tackle - but I just think theres gonna be a LOT of red cards if they send people off for that. Might aswell outlaw the slide tackle altogether. Koumas tried to play the ball, and the tackle was no higher than the ball, with one foot. Yellow card seems sufficient to me, but it wasn't as bad a decision as I thought it was on first viewing when I thought it was ludicrous.
I thought his foot was too high Maybe it was harsh, but I still think it was a bad tackle and I can understand why the ref made the decision.