He wasn't trying to slice his achilles but he was trying to take his legs out from under him. Just another example of Cooke's long history of "unfortunate accidents".
I'm more in this camp than the "Cooke intentionally stomped on Karlsson" camp. Though, given Cooke's history, I have no problem with people who believe that. Cooke is a vile scumbag.
But I think he was trying to slewfoot him and it just went horribly awry. Which is why I've been calling it reckless, not intentional. I don't think Cooke set out to injure the guy... he just didn't care if he did. But Cooke already used the "it was an accident" excuse when he pretty much ended Savard's career. And he used it when he popped Lecavalier in the head. Neither hit got a suspension.
Matt Cooke... almost went 23 whole months without ruining someone's career. Good thing players were locked out for six of those.