I'm a little late coming into this, butttt......
Controlling the fight or flight is definitely a learned behavior. You have to train youself in order to remain calm. There's no doubt about that. I'll admit it is difficult to do sometimes, but theres no reason a person can't learn to control it.
Yes an attacking dog can be a bit intimidating, but they are predictable. It's actually quite easy to disable an attacking dog with your bare hands if you remain calm and can predict the animals next move, which will be going for the kill or an attempt to disable you.
I must admit if someone "trained" themselves to remain calm during a dog attack on them or a loved one, and actually DID remain calm, I would be shocked.
At the beginning of this year, my adorable daughter was playing by the couch where our dog Kayla was laying. Zo was talking, laughing, doing what any baby does at 15 months old.
I was sitting here watching her play, smiling as I usually do, and she leaned over to Kayla to give her a kiss. She's a very loving baby...
At that moment, I heard Kayla growl at her and she moved toward her, knocking Zo down (and of course she started crying because she was scared). I flew up out of my seat, without even thinking, and leaped toward Kayla. NO DOG, even my own, will do that to my precious baby.
I was crying, screaming, and ended up with a broken blood vessel in my hand. I chased her through the house until I could get a hold of her to take her to her cage.
I understood that Kayla most likely didn't like Zo in her face, and to this day I have taught Zo not to do that. Shoot, whenever she goes near the dog, Kayla moves (I think she remembers lol).
All in all, she's a sweet dog. She just doesn't like anyone in her face (like a lot of dogs that I've come across) and that night she let us know that. We haven't had any problems like that since.
The thought of getting rid of her crossed my mind, but I love her dearly. Granted I love my kids more, but Kayla is just like my kid. I just make sure to keep the kids out of her face and I NEVER leave them alone with her.
I guess my point is, being calm in a situation like that is very hard to do. If someone is capable, then I applaud them. I personally don't think I could keep "calm". My adrenaline was pumping and I was furious. A little scared, yes, but I acted quickly out of fear that something would happen to my baby. I think it was just the "mother's instinct" in me.