Danger! Professionals at work
I don't know if the "professionals" are alergic to safety devices, or just lazy; but I've never seen a carpenter with the blade cover not permanently disengaged on their saw, or a framer with the safety still on his nailgun, or a shop with the guards still on the grinders. I was helping out over at a mechanics shop and asked for some safety glasses before using a hand grinder and it took some serious looking around for them to fine a pair. Sigh.
Combine no safety guard with a location with a view, and the outcome is of little surprise. I mean, how many times have you been grinding or buffing a small part and you press a little to hard for a moment and the part is whipped away out of your hand? Happens to me all the time.
At least nobody was watching through the window.