There are few horrors that lurk in the deep places where man has not yet trod that can rival what happens when you play a game made by Bethesda. We've begun to suspect that either their developers are adding these nightmares intentionally or their office is haunted by the ghost of a shitty programmer. So it should come as no great surprise that characters in Skyrim will occasionally swim through the air.
"Sometimes I forget I can't just pee like I'm in a pool. That's why I'm no longer allowed at church."
It looks odd, but the characters otherwise act the same. You can still talk to them, get quests from them, or bash their head in with a giant ax and steal their shoes. But under the right circumstances it goes from a silly, trivial little glitch to skin-crawling horror. And here those circumstances are!