ydi for letting your child carry around a toy gun in a place like a bank, what did you think would happen?

That is funny and sad

If your son scares that easily now, I can't wait to see how he turns out in his teenage years.

My younger brother has a realistic toy gun but my parents taught him not to use it outside of the house because it could be mistaken as a real gun. OP should have taught her son not to use it in public.

Ummm...YDI. I wouldn't call the teller "dim-witted" for hitting the silent alarm. It could've very well been a real gun -- you yourself even said it was "realistic looking". And 8 year olds (and younger) are quite capable of pulling a trigger. Don't let your son bring something like that outside of the home and teach him how to behave in public. He's old enough to know that behavior like that, especially in a bank, is just not appropriate.

Why did he have one with him in the first place?

I don't understand all the YDIs - it was the son that pulled this shit, not OP. We don't even know if OP knew his son had a toy gun.

This is why you don't have children

You are the dim wit,not the teller.

Control your kids