I don't know about this exact situation but I flew Angel Flights for years with just a PPL in my own plane. The FAA went after them years ago and Angel Flight had their lawyers push back and got a ruling in their favor from the feds. The fed was claiming that even if you flew for free you were being compensated with the flight time and the tax deduction which is just another example of the government being out of control. You can look on their web site and find the info or at least you use to be able to.