I read this whole thread (yes, every post) and the defense of the people on this forum, we get very emotional when we see an animal in distress. It brings out protective instincts in us that, no matter what harsh words or assumptions we make, at the end of the day all we want to see is the animal taken care of to the best of the owner's ability. It's hard to see anyone's pet in pain or in a situation like yours, and I'm glad it all worked out.
To everyone here, shame! You can't assume anything through text. The OP could've been crying their eyes out as they wrote this, desperate for some reassurance that their baby will pull through. You never know what an owner is thinking, but by just posting on here shows that they knew something was wrong and came to what I think is the best resource on the internet (even for non-reptile problems!). We need to live up to that reputation and have a little less pointing fingers and a little more informing and helping. Yes, getting that snake to a vet ASAP is what needed to happen, but look, that's what they did!! Assuming makes an "a$$" out of "u" and "me"!
To OP, I am so glad your baby will be okay! All I would say is to have a talk with your brother and remind him that Ball Pythons (especially babies) are extremely delicate. If he's only had experience with hots he might have a too-rough approach and should tone it down. The instinct to stop a strike if he's a hot handler might be a no-thought reflex, so some caution might need to be exercised when he's around your little ones.