He's not gone over the top of the ball, he hasn't intended to do the player and what happened was the unfortunate result of a mistimed challenge. You see them all the time; Pienaar's second yellow against City was the same. If his foot came down and had broken a leg, we'd all be saying it's unfortunate, not malicious.
It's the same with McManaman. Whelan is 100% correct in his assessment of that tackle - he's went to wrap his foot around the ball mid-flight but the ball has spun away before he did and he's caught the lad coming in high as his foot was coming down. There's no stamping motion, no straight leg, nothing.
There have been far worse in terms of intent this season - with all bias aside, Suarez doing Mirallas and Distin was horrific.
As long as the game of football involves a ball that can bounce in between two players coming towards the ball, tackles like this can and will occur.