There seems to be an aspect here none of touched on, and this is in no way an excuse for this man, but from the conversation / behavior this would not surprise me.
I have had a few dealings with elderly people, including own family and strangers. The way responded and behaved, it could be that he is not 100% there, in the sense that there could be some dementia in play.
I have seen elderly people go of on others, also on my for no reason at all, simply because they are suffering from mental health / dementia due to their age.
This was more based on the observation of his demeanor. This does not excuse the situation, but it does make it more complicated.