What if Soviet submarine B-59 had fired nuclear torpedoes during the Cuban Missile Crisis?

https://en.wikipedia.org/wiki/Soviet_submarine_B-59 One of the truisms of modern war is that the world cannot possibly survive the detonation of even a single nuclear weapon. Now, given the rather small, ten ton yield of the smallest A-43 tactical nuclear weapon -- rather less than the largest conventional weapons, like the MOAB -- this truism seems rather unlikely to be true. However, most tactical nuclear weapons have yields at least in the kiloton range. And, the nuclear torpedo on the Soviet B-59 submarine used during the Cuban missile crisis was 10 kilotons, not much less than the yield on the Hiroshima A-bomb. Effectively, it would have annihilated all of the U.S. ships in the area. As it happened, the senior officers split on using the weapons, so, they decided against it, even though the U.S. forces were using depth charges against them. Suppose, though, nuclear torpedos had, in fact, been used. What would have happened next, exactly? Arguably, the U.S. should not have been using depth charges on a submerged Soviet submarine that had been out of contact with the world for days, and might have thought they were in the middle of a thermonuclear world war. Personally, I would suggest the U.S. actions were not a terribly great idea, under the circumstances. So, if the Soviets had fired a nuclear torpedo, it would not have been entirely unprovoked, by any means, at all. But, obviously, the U.S. is going to have to react to this. What do they do? First of all, I would suggest the U.S. would check its early warning system to see if any Soviet missiles were on the way. They weren't and, this would be somewhat reassuring. Presumably, Nikita Khrushchev would be made aware quite quickly of what had happened, and he would want to deescalate. What does Khrushchev do? I would suggest he calls President Kennedy -- there was no "hotline" until 1963 -- and indicates this was a terrible mistake, and he will agree to demilitarize Cuba immediately. All Soviet troops will leave, all weapons systems removed, the U.S. can have Carte Blanche there. I would suggest Kennedy might well accept this offer. Fidel Castro would be removed from power, Cuba might even have become a U.S. territory. There are many other possibilities, of course. The U.S., which at the time had a sizable advantage in terms of nuclear weapons, might well have launched a first strike on the Soviet Union, effectively annihilating the country, and the Soviet Union would have responded by nuclear strikes on Europe and the U.S. Probably hundreds of millions killed, worldwide. Alternatively, the U.S. might simply have launched a nuclear first strike on Cuba, effectively totally annihilating the island, and everyone there. And, that might have been the end of it. Any other thoughts?