Would you withdraw your savings from a bank because the cashier didn't understand HTML 5? Why should we not assume operating a cash drawer is roughly equivalent to HTML 5 knowledge?
I wouldn't expect the cashier to be selling me a product they didn't understand either. If my bank tried to sell me a new security because it was backed by custom chips running HTML, I would probably switch banks as well.
Lying with confidence is, after all, where the "con" in con man comes from.
2. It’s not the lack of understanding that’s concerning. It’s the confident wrongness.