In safety, working while being frustration is risky. Just imagine, what will happen if a forklift driver is angrily turn his truck which is carrying pallets fully loaded with chemical pails. No need to ask why he was angry. The chance of the forklift to overturn is high as same as the risk of dropping chemical pails and spill them on the ground.
When we frustrated, we usually forget to think twice. All we do is just blow out the temper onto something. Have you ever drive when you are in bad mood. How was it?