Water probably wasn’t at 150 when he first turned it on. He stepped in too soon... those cool pipes can have the cold water pushed through them with the blazing hot and catch you by surprise. What you are used to at home can lull you into thinking the same in a different place.
He is 76 yrs old, no telling how nimble he is, but a 150 blast is a lot of heat on a thin skilled older guy...or a toddler.
The water going to rooms where guests of any age can be, shouldn’t be that hot.
He probably would have been OK or just minimally hurt if he hadn’t also slipped and been scalded for a long time. How long it doesn’t say.
He may have been a guest of those renting the room rather than one on the hotel registry. People do that to avoid extra charges.
The person screwed up and then cashed in on it. No shortage of those people I’m afraid.