If the homeowner is being asked before the drilling happens if it is ok to drill in certain places, doesn’t that absolve most of the blame to the home owner? A technician can’t possibly know where everything in the wall is, and they usually point where they will drill and have the homeowner agree.
There are shitty technicians that don’t, or that don’t measure/remove drop ceiling, but I wouldn’t lay the blame solely on the tech in every case. Installation is a cooperative process done by both the technician and the customer. If the customer is aloof, he shouldn’t be surprised when his jerry rigged piping through the garage gets punctured.