See, and this is what I was thinking - as long as there's no blood and nobody's crying, they're fine. Two little boys wrestling, one is going to get the worse end of the deal. So Mommy comes running, having a fit - way to wussify your kid, Mom.
It not really accurate to analogize this as kids on the playground. But if one kid outweighs the other by say 30-40 pounds, and has just knocked down the little kid (think a 3 year old 10 year old, thats maybe the size difference we are talking about here) twice, is it having a fit to want to separate them? Picture a toddler and a 10 year old, how many times would you let the 10 year old push the toddler down before intervening? Keep in mind, one dog was 40 or more pounds, 2 feet or better at the shoulders, while the other was less than 10lbs and maybe 8-10 inches at the shoulder.
And it wasn't playful pushing around or rolling around. The dog just smacked the little one down, a stomp to the head. Twice in less than say 30 seconds.