And on the opposite side I'm curious who personally was that American who decided that attacking a Russian nuclear-armed submarine in international waters with depth charges was a good idea.

The Navy authorized use of practice charges to signal to Soviet subs near Cuba during the Missile Crisis. They were practice depth charges, meaning they were small devices not intended to damage submarines. The US Navy says they informed the Soviets that they would use practice charges to attempt to signal to Soviet subs that could not be hailed with normal methods. This sub had been out of contact with Moscow for quite a while.