He was pretty much verbally destroyed by the factory manager.

I don't know how much pull or freedom of choice or responsibility the factory manager has with the workers. IF his role is also as a supervisory office type position, and he had no clue one of his employees was having problems then he needs to be talked to also. Verbally destroying someone in just about all cases is pretty uncalled for.

The factory manager it would seem needs a little bit more people training, I am assuming he was aware of the previous incident, and is aware of the company wanting to help the employee that screwed up grow with the company to become a valuable asset.

Emotions can run high at times in stressful events and times, here there were two screw-ups, two mistakes made, the miss-wired piece of equipment and the handling of the results of that mishap.