I agree with Pop 100% on this one. When a player is in the air, he is vulnerable. You don't undercut a player who leaves his feet and you don't side your foot into his landing zone. It's a dangerous play that puts a player at risk for injury. I don't give a shit about intent. When you make a play that puts another player at risk, you deserve to be penalized for your actions. No one should have to try to guess you're intent.
Either you did it, or you didn't. Pachulia clearly slid his foot into Leonard's landing area and Leonard did land on his foot, rolling his ankle. It was Pachulia's reckless action that caused the injury. It was a dirty play. You just don't do that shit, whether it's a rec league game of the WCF.
BNM