Not that this ever happens but...
Some one comes in for a simple adjustment. One temple is bent way out making the eyeglasses obviously uncomfortable. You take it back to the lab and with the correct plier you adjust it and it breaks right off. The frame while not brand new is in otherwise good condition. No warranty available, the make/model of the frame is unknown. Lets make it tougher by saying there's colored enamel that makes a quick weld not a quick answer as it will burn off the enamel. He's out there waiting....what do you do??? At who's cost??