Okay but seriously, how do you even define topping in a case like that? Sounds like you did a huge reduction cut, not a random hack job. I agree with park.emery that rules get bent in real world salvage. The "never top" rule is for clueless homeowners cutting straight across, not for making the only bad choice left to keep a tree alive. Those new shoots on old wood can be weak, but a strong lateral like your 10-inch one gives a way better start. It's all about the details most people miss.

My buddy almost quit too, but then he got to the chess scene and it just clicked for him.