[15155]

There's no way someone is "barging in" with a door chained (with normal-style chain or a bar-style chain) in under 30 seconds, probably a minute or more of finagling the long tool into place to get it undone.

While this is happening, the person on the inside can totally thwart the attack by just blocking the tool physically - it's hard enough to do this while you're not being interfered with.

[gs17]

Sure, but I imagine the security guy checking in on you doesn't just say everything's okay and leave if you do that.

[15155]

The idea behind forcibly stopping someone from barging into your room is to slow down the interaction and gain control.

The goal is then to establish identity, purpose, and ultimately deescalate. And then if need-be call the police and/or chargeback your credit card later.

Until otherwise verified, this intruder is no different than a random burglar breaking-and-entering in the middle of the night.