Regardless of whether this was an accident or a regular occurrence, you did the right thing. The police can determine if this was an accident or not, and since the owners weren't home, calling them was the thing to do. The dogs threatened you, and could do the same to a small child. The owners will just get a warning and that will serve as a wakeup call to check their doors, gates, and fences for places that their dogs can get out.

If you're concerned at all about your neighbor's feelings about this, I would call them or see them and just explain nicely what happened. A couple of years ago, we had to use pepper spray on a neighbor's dog that got away and was literally attacking our dogs, who were leashed. As their dog was rolling on the grass, wiping his face, the owner came out. We explained, and he was very nice about it. Later we found out that he had been reported by our mail carrier to have a harassing dog and was instructed to move the mailbox off his porch and onto the sidewalk.

Anyway, I'm glad no one was hurt. Sometimes we just have to these things.