Yes, It is. Using heat to expand the gear so that it easily slides on to the cam is the standard procedure. When you pay any shop to do something it is on them to do it right. At the very least they need to put it in writing that they guarantee that the gear will stay put and that they will fix anything damaged by a failure. You need to let them know that they might want to update their fire insurance.
"I wonder if God created man because he was disappointed in the monkey?" Mark Twain
