Wow!!!
Before I say this, we've all done it, at least at some point to build hours...I'm talking about "illegal 135 flights"....
On this occasion the pilot apparently didn't need to build hours, however, "take passengers, drop passengers, get more passengers"...Doesn't really sound like a Part 91 flight to me...
I'm sorry about the outcome, and while I somewhat understand....as I said...As a newly minted Commercial pilot working as a CFI...I can only thank my lucky stars that I didn't kill anyone...and that was in 1978...