This seems to be the point at which the volks stop, unless I'm watching incorrectly (this is the earliest point where it looks like the volks begin the reaching for their rifles animation instead of having their hands on the ground). I agree that this would be too fast reaction time from Seeking, but on the other hand, why would he wait this long until the pathfinders are at this spot before canceling the sandbags? Why wouldn't he have moved his volks to an optimal position to the green cover right there before the Pathfinders reached their green cover? It would be nice to see this clip at normal speed from Seekings POV for the duration (it only has POV for a small portion). If there are desync issues in the game +/- 1 second (I believe there are) then wouldn't pretty much all of these cases of pre-emptive moves fall within the margin of error?
I checked frame by frame.
This is the exact FRAME where the volks stopped building, aka there is no point in time before that to show it happened earlier. This is the moment the Volks stop building and the Paths are not spotted yet. Now let's see the 1st frame where the paths are spotted.
Almost a full second passes, the Volks have already picked up their weapons and the spios are about 1m away from their previous position. There is no doubt whatsoever that the decision to stop the sandbags was taken before spotting the pathfinders, no matter what kind of delay you account for.