Yes, that's always a possibility they can make things worse, it took them three tries to replace a windshield properly (glue everywhere, wind leaks). 3 times to upgrade cameras correctly, but other times problems are corrected the first time. Once I had an annoying rattle in my Lexus dash, after three visits, the problem is lessened but not completely solved, the dealer offered to completely reinstall the entire dash but cautioned it may cause other new rattles ... For Tesla unfortunately you just have to adjust certain expectation but enjoy the vehicle, it's technology, battery, and charging network is still superior than others at the moment.