Creepers will still see you and blow up even if you are behind a door and the door is shut.
MCPE-27212
Creeper Blows Up If They See You Through Door
Resolved
Fixed
1
I have also seen this in 1.2.3 - on Xbox one
I was playing multiplayer, on someone elses REALM.
I was in a naturally spawned house (village), shut the door (oak) and the creeper walked past, saw me and went BOOM!
I'd only just put a fresh coat of lacquer on the door too! 😛