I though he only had cams? And it the shop didn't feel like the car was "safe" to mod, they should have advised him of that. Just my opinion. Untill the OP chimes in, really cant speculate.No. That's part of what is wrong with society today, self entitlement and placing the blame on others.
In this hobby, we choose to modify our vehicles far beyond the design of what our cars are meant for, but yet when something goes wrong rather than taking responsibility for it they rather look to place the blame on a shop that was paid to do the job. The shop can't be held responsible for modifying a car unless they are grossly negilgent for something like leaving a lug nut off a wheel or something. lol.
The owner is ultimately responsible for making the decision to modify his/her own vehicle and accept whatever consquences that come with it.