I always thought that if you got to log the time its was benifit in kind. So therefore deemed as a payment for the service of a check ride. Also the cost sharing rule comes in as well
The quoted i think refers to a ppl pilot doing a maint run as a favour. As such no money has changed hands.
But as its a very long time since I had to worry about if the flight was legal or not if someone else pays. I am sure your proberly correct bookworm.
MJ