Basically, what I saw: two zombies trying to get into a villager home, so they were both trying to break in. But once they both started doing that, they seemed to be pushing eachother away from the door, against the building. So they were sort of slowly sliding along the building, which looked pretty strange, while the scorch marks on the door remained.

After a while they both were strapped back to the door and the whole thing started all over again, without them being able to break the door. This was on SMP.

It's not a big deal, but that shouldn't stop it from being mentioned