I don't disagree although another thing I thought after watching and rewatching a few times is that MD doesn't even seem to notice Kaylee convulsing, she doesn't appear to look at her at all as she steps over her, and the rest of the gathered kids don't seem to notice it either, which is just as bad but in a different way.
I agree with you. She doesn't look at Kaylee. It's almost like she is on autopilot.
She likely had cortisol and adrenaline are both stress response hormones, which contribute to the 'fight or flight' state, which I assume both girls had coursing through their bodies, and likely many of the others starting break-off fights.
They are extremely powerful hormones, especially in teenage bodies.
With that in mind, I could see that MD saying she 'blacked out' could be her way of explaining fight or flight. Additionally, some people have problems with their hormonal response on a chemical and pathological level, causing low or high emissions of certain hormones.
The point is, I could see a normal stress response to actual physical malice being fight or flight and (after choosing fight in this particular case) trying to defend myself but also being hyper-alert to the fact that there are fights where maybe people I love or friends are being attacked or attacking themselves and wanting to help them, either to stop them fighting or stop an aggressor.
This might seem too theoretical, but it is scientifically shown that these responses and hormones are fact.
I have experienced this rush of hormones several times for many different reasons. One significant time, I was eight months pregnant with my third child, and a young mother at my elder children's school came storming over to me, yelling and threatening me because my son had run in front of her child on a scooter and her child fell off the scooter, a playground occurrence everywhere. My back spasmed, my knees wanted to give way, and my heart was faster than an F1 McClaren. A random adult took control of yelling mum, explaining it was an accident, and another random mum swooped in to ask if I was OK. I didn't fall, but it was the most intense feeling in my life. It took a good 45 minutes for my heart to settle, and ever since, if I ever have a stress response, my back spams very lightly, almost like a memory response. I assume the fact I was pregnant was why the response was so extreme.
Yet, I had absolutely no control over how my body reacted.
JMO and some food for thought.
ETA:
grammar