Fairly sure I'd want to keep him as long as possible, like a pet. One I didn't need to feed. Or clean up after.
It's more likely the player noticed the key was gone, either looking at the backpack or when trying to enter the home. Would be the easiest way. Trash barrel security cannot be passed unless the owner chops it up without replacing it. This rarely happens but I could imagine a careless house owner leaving the spot clear if bringing an animal/mob/friend along. That'd be your chance.
You must be new.. 1.) If you have a key to someone's house, but you do not own or co-own the house, it is not possible to chop a trash barrel. 2.) The reason you cannot teleport anywhere inside the house is for this exact reason. If teleporting over barriers inside of people's homes was possible, everyone on this server would end up having all their possessions stolen. As much as I imagine you would personally enjoy that, it is not conducive to protecting the player base. It would have a very negative consequence on the server. 3.) If you were hidden inside of someone else's home, and you are not at least "friended" to that home, if you're log out of the game, and then back in, you will be placed outside of the home. This has always been the case. 4.) Part of securing your home is for people to build barriers in the entrance of their home, like the one you encountered here, as a measure to protect their belongings from thieves. In addition to that, when someone returns to their house, most people use the detect hidden skill to reveal any hiding marauders that might be looking to cause trouble. Once they reveal you, they simply say "I ban thee" and then target the person that was revealed hiding. I assume this is what happened to you. 5.) Once a person dies and loses their house key and rune, you can pretty much bet they will quickly be changing their house locks, which is also what happened to you. 6.) As a theif, you aren't very covert when you take a screen shot of your actions, and then post them to the forums. I would be shocked if you were actually surprised by this.
Actually yeah, I am new. And the whole experience of nothing decaying inside houses is the first I've ever heard of since I started playing 17 years ago. So you'll have to forgive me of my newness. Most of my post was for fun and sarcasm, but I truly needed help getting pass, which is why I posted it in the forms. That part was genuine.
I'm slowly catching onto things here, and my buddy is starting here, so things may become very interesting real soon.