Look at this way: Cylinders 2 and 3 have zero compression, while 1 and 4 are normal.
What are the chances that both of those rings have gone
so bad that compression reads 0, while the other two are fine? Probably next to nothing..
Whatever it is is probably not cylinder specific. I don't really know where I'm going with that lol, but that's how it looks to me. A head gasket leak between the two would give you bad compression too if the two cylinders are not in phase together but I don't think it would show 0 even then