Originally Posted by jadocs

This is like identical....

OP you as mentioned over and over, you need to have the "shop" show you how their equipment didn't do the damage since it is consistent (as shown above) with damage caused by monkeys doing bike repairs. Tell them it's for your own piece of mind. If the owner is reasonable as you say, this should not be a problem. Once it is shown that their equipment caused the damage...now it's their problem.

and for God's sake...learn to do simple repairs (even more complex repairs) yourself. Nobody is going to be as careful as you on your own equipment.