Just finished watching Nature on PBS. Tonights show was called "Hippo Beach". The "Beachmaster" (alpha male) climbed out of the water in the middle of the night, chased off two lionesses and munched a dead buffalo they were eating.
The narrator said it was rare but hippos do eat meat occasionally. Especially the alpha males that are busy defending their pods (ho's) and procreating so they don't have time to eat properly.
Guess it's like the health food freak going to McD's in a pinch.