Can’t say personally seen any of the security footage but from the sounds of it this guy was mingling with the crowd and not drawing attention to himself as well as able to book it down the alleyway. It’s not improbable that he’s terminally ill himself, but it’s hard for me to believe he’d be at a stage the doctor(s) said he was incurable/insurance denied him but still not far enough along it’s not affecting him in anyway noticeable way.
Having lived with two orange cats before, can confirm that look almost always precedes a cunning plan. And often a loud bang or crash, and then a sudden mess.