He remembered how the demon had tried to rape her.
"You mean demons will try to make me think that they are those I love?"
The demons were only trying to help, in their fashion.
But a demon tried to kill him and almost succeeded.
The demon was trying to get in another way.
The demon was still trying to break in from the other side of the house.
It was after all possible that the demons were merely trying to make her think she was going wrong.
The demons were trying to drop the slab and his friends into the fire before he could reach them!
Why do you think demons try to kill their summoners?
Angel does not know which demon or monster is trying to set him up.