As a shop owner I have to say this is true. Even I have 1 or 2 people that I have not been able to please. The 4 problems as I see it from my point of view from reading most of this mess.
1. The owner has lost site of the fact that he no longer has a stock car, once a car is changed from stock form a chance for problems grows and on a boosted car of more the a few years old it grows alot.
2. The owner did not fairly voise his feelings so that they could try to fix them. Ips is not big enough to not care about word of mouth so I am sure they would have tried to make him happy.
3. They should have told the customer they needed to rewire the part and then if declined put that fact on the bill.
4. Jeff I don't know if I have met you or what greg's total job is but I would suggest letting him speak for the shop as most of the time he has a more political tongue than you, wining the e-battle may make you to lose in the long run