From the video, the police said they didn't have a reason, except the management wants them out.
I understand the right to refuse service but after check-in, you assumed responsibility of the guest.

He did seem like he was woken up and shaken by the situation. Had he been disturbing the peace, the police would be rough on him, not getting him a cab.

Then again, if 'pranksters' can be thrown out of the hotel during the stay, can the same be applied to an ex-convict when the management deem it a 'risk' in the middle of the night?