You say you're an engineer( I don't believe it) but you apply McDonald fry cook type management to professionals. You are stupid on top of being a total prick.
The HR question was about medical coverage. They weren't asking if he could calculate the moment of inertia of a structural cross section.
“They weren’t asking if he could calculate the moment of inertia of a structural cross section. “
I don’t think you could manage a moment of inertia sufficient to roll out of bed and show up for work even if you had a job.
Keep in mind that the position under discussion IS for a "clerk/cashier position", not trauma surgeon. As such, since the position involves dealing with customers all day, the attitude of the prospective employee is a PRIMARY factor in the hiring process.