Meh. If it was a porch IE separate from the hallway or what have you, then I don't see an issue.
I'd have expected a knock first, though.
Are you certain your wife didn't leave instruction to do so? I've actually done this before when I worked as a delivery driver and never had a problem. It felt a little intrusive to do but ultimately I was doing them a favour...
Also got loads of free shoes out of it.