By definition, a mike that is "stuck open" is not a mistake. It is not an intentional offense.
It is a simple technical breakdown!
Yes, the spring in mike switches sometimes fails, and when it fails, the mike can stay "open" after you have let go of it.
Yes, an astute radio operator should notice their radio hasn't come back into RX mode or that the TX light is still on. Shoulda, woulda, coulda.