This is when you should tip.
Why? We don’t know anything about this guy. Maybe he was dumped because he was cheating on her, or abusing her, maybe he was kicked out because he hadn’t paid rent in six months.
Maybe it’s a dick move to assume the negatives. Maybe he has opportunity to learn a lesson. Maybe he’s on the verge of homelessness regardless. Maybe he’s still a fucking human.
But why does that mean I should tip?
To quote an eastern european woman who said this to her 10 year old kid on the subway: “you see homeless, you give money.”

probably because he’s willing to still take the trip even though his life seemingly went to the gutter.

Also he seems considerate enough to let the passenger know, and if it WAS his fault he seems understanding of it