Yes, "based on my conversation with a person waiting to pick up one of the workers".
When I'm sitting there at shift change and "NOBODY" else is driving into the parking lot at 10 minutes before the shift is over I am going to think the person is telling the truth about there is not a 2nd shift!
I can confirm "from that same unreliable source" your contention that they can run out of parts, because they mentioned that the person they were picking up didn't get to work 2 days from the week before because they ran out of parts.
I've given them the benefit of the doubt, I just don't believe I can go up there on random days and can never find a 2nd shift working.
GLTA, GOODH2O1