Stolatos wasn't running forward. He was basically walking. You asked him to attack like he had with Ben, where he also was walking. I didn't say anything about him charging forward... Because he wasn't. More then enough time to plant his foot before the attack struck as his foot was already moving towards the ground.
I didn't defy physics, I used it. By applying more weight to his leg he makes it that much harder to have it kicked out from under him. As you neglected to mention where the kick was aimed or how hard it was, I had to assume it was a generic leg sweep. With the added weight, Stolatos would take more blunt force from the kick but given sufficient weight would not have his leg kicked out from under him entirely. And his other foot then moved to catch his balance which was somewhat off-put by the sweep.
Is it possible, even if just for a couple more posts, that Raleigh teach Lucifer djem so? Even though the class is all leaving, I'd really like Lucifer to learn the form for future story purposes, even if this thread moves to the back of your priorities.