Norrington had been expected elsewhere, yes. Quite some time ago, in fact. With that in mind, perhaps it should not be too surprising that there is a knock on the door.

"-Mr Norrington, sir?"

The door is not locked, so Wellard pushes it open. There are quite a few reasons as to why he thought Norrington was late-

By the narrowing of his eyes as he sees Aphelise, this was not one of them.