A lot of advice and experience has already been shared, but I want to reiterate: Verbal agreements are tricky-- but regardless of legality, it's super shitty to get used and ghosted in any capacity. Your friend is right to be upset at being led on then not even given the courtesy of "hey, something happened last minute. Here's compensation for your time," which was wasted.

I don't care if this is "standard" or "not unheard of" in industries-- kudos to your friend for sticking up for themselves and not rolling over.