The extra strength from the stretch reflex is only a positive here. You are loading the muscle with more weight. More weight = more tension = growth.
In fact guys like Benni Magnusson use this to overload more in training. He starts his deadlift from the top by picking it up from a rack.
"More weight= more tension= more growth" In some cases YES but in this case, NO.
Let me explain.
We both agree that if the deadlift was performed correctly for 3 reps (with a pause a/f each rep) then less weight would have to be used, weather it be 30lbs or 50 lbs less.
You see even though more weight was used....... there was also a tremendous amount of momentum used to bounce the weight off the floor. THis does not EQUATE to a heaver LOAD on the muscles. WHY? Because elastic energy and momentum was used to bounce the weight off the floor, the muscles were NOT doing all the work, momentum and elastic energy was used to "bounce" the weight off the floor.
The Visual proof of this is in the Vid when he hardly got the first rep and yet the last 2 reps were EASIER then the first. This is undisputable proof to support my point.
The muscles would have experienced a greater "growth stimulas" if 575 had been used for each rep with a 3 second pause b/t each rep. Less weight would have been used , HOWEVER there would be ZERO momentum and elastic energy to assist in the lift.