I work in a high intensity environment and things do get heated. I can also say that there is always two sides to a story. Maybe the owner was having a bad day. Maybe already had to redo something for someone else for free or even worse, got summons to court for another car and his fuse blew on this one.
I am a firm believer in moving forward. Find a mediator (someone else that you trust and frequents the shop) and have them talk to the owner and see if he would patch things up.