I read somewhere that they have no way of finding a player from a pet name. So if you told a GM about a pet with an inappropriate name, they would not be able to trace that back to a player or account.
Saying that, these people must have used a bit of imagination to get these names in. I sometimes can't even get things past the name filter that are completely innocuous and not offensive at all. I guess I can (sort of) understand why they blocked "ball" and "hot" but seriously what is wrong with words like "zigzag" and "chef"?