@HF
The video you linked.
Play this part at 0.25x speed and see how Thor was swinging his arm (and his hair, ha, fab) faster than most everything else except the repulsor and Pietro himself, and they're in free-fall. I brought this up earlier, and a long time ago that Thor has slightly faster combat speed than the rest. Not too big, but quite noticeable (I can't remember anyone dodging his hammer throw).
This however, does not justify MHS. How fast was the slow down was, is something we can't answer (unless a calcer can do that, in which case, we can) and therefore can't quantify how fast Thor was there.
Regarding Thor throwing the hammer at Pietro, I brought it up with Gwyn a long time back as well, and he said we don't know how fast that thing is moving, and we can't compare it to Pietro's staring at a bullet flying upwards because those are different scenes with likely different slow downs.
I kinda agree with Gwyn there that it's unquantifiable. We don't know if the slow down is the actual reflexes of Pietro, and if the slow down for the hammer throw and the bullet is the same.
Lastly, Pietro was quite literally running in circles at that point because he doesn't have much else to run on. They're in a confined space, and he's running on a catwalk. Thor can just see him blur around from the other side of the structure, and assume he'd come from the direction he came from. Not to mention the fact that Pietro had to slow down since he had to turn a lot in that confined space as compared to the rest of his showings (only the train scene had many turns, and it was far more open than this).
Bottomline, we don't know how fast Pietro was circling around the catwalk for Thor to see and react to him.
