Back in the 80's, I interviewed the rock band Kiss. Cassette recorders were a bit more primitive then, and I found to my horror that my machine had not taped the interview.
Gene Simmons was courtesy itself, he not only invited me back to the band's hotel to re-record the interview, he offered to let me record it on his own state-of-the-art recorder - which would be worh the equivalent of about £600 in today's money.
After Gene and Paul left, I realised that he had left his recorder behind. Being an honest soul, I packaged it up and sent it to his record company in London for them to return it.
I thought afterwards that a multi-millionaire rock star probably wouldn't miss a tape machine - and the chances of it actually getting back to him, and not into the possession of a record label employee were probably pretty small!
That said, my concience would nt have let me just keep it.