Actually, they're stuck between a rock and a hard place. What did you do wrong? You're not the bad guy here by any stretch, don't let them make you feel that way. You're a professional and your neighbor should've known better, but decided to save money using family for the majority of the work and decided to use you only where he has to.
You can always use the ole "My insurance company would dump me in a heartbeat if I connected someone else's work!" line. BTW, don't loan this neighbor any yard tools.
Andy
