High speed video has shown that the springing back takes much longer than the tip-to-ball contact, so it has no significant effect on the energy transfer.
If someone is stabbing at the cue ball that may be true, but someone accelerating through contact will have a different effect.
It will have an affect one way or another, either increasing or decreasing the effect.
The timing of the springing back will be influenced by the stiffness/flex of the shaft and will vary from shaft to shaft so high speed video will only show the results from the individual shaft used. Also, was the shaft used a 13mm or 12mm shaft? This will also reflect the end result.
To claim that those tests proved anything is in all reality is a false statement unless each scenario was included in the testing.
We could also throw another wrench into the result by showing that the various tip hardness will also the affect the outcome since a softer tip will indeed absorb more of the impact shock than a hard tip will.
Machines can only determine a limited amount of end results depending upon what is being used in the test, and lots of what has been stated concerning these results can actually be scientifically and mathematically eliminated.
A prime example is the different amount of deflection between a maple shaft, a keilwood shaft, and a cf shaft. -
Now throw in the difference between different mm shafts and you have another issue to deal with since each one reacts differently.
