Examine text of saradomin warrior claims it as zamorak.

Edit:
You are also able to attack players through walls who are in their safe base.

Attacking players through the walls will be fixed. I yet have no idea how the warrior got into there though.

Idk if this is normal or not, but apparently, if you run with the flag, a zamorak warrior can chase you all the way up to near saradomin base and keep on attacking you. It is like a target finding thing. After that, it will slowly walk back to its own base, but however in the middle of walking back if it was attacked again, it will retaliate.

Yeah all Castle-Wars npcs can do pathfinding. They are supposed to be nasty opponents!