I am glad you are consulting with Dr Couto, he is a wonderful person. It could be "just" a break, and I hope it is, but you want to be sure. I don't want to scare you, but I was told Sallie's was "just" a broken leg, but Dr C (and my own vet) saw the osteo right away
What ever happens, do NOT blame yourself! You have taken as good care of Jake as anyone possibly could, sometimes accidents happen.