Not sure this is enough for an answer (this was going to be a simple comment), but here goes...
I'm not an expert, but I've seen that most adult dogs are quite considerate of puppies, meaning they won't try to hurt them (and even try hard to avoid it). If "the puppy wasn't actually hurt", it was most likely the intended result from your older dog.
Do keep in mind that most of dog behavior patterns are alien to us (and let's not get started on smelling and licking) but it is the way they communicate with one another and set boundaries. Some puppies even play very rough between themselves.
I don't expect you should need to stand guard for the next day, let alone 15 years. Plus, I bet the puppy learned the lesson.