It depends. There have been lots of theories that turned out to be false, usually from incorrect assumptions. One example that keeps coming up for pool is that "physics says" that the nose of the cushion ought to be at exactly 70% of the height of the cue ball. This has a grain of truth from physics -- if a cue stick strikes the cue ball at 70% of its height the cue ball will immediately start rolling without slipping. The pitifully wrong assumptions that go into this hypothesis are pretty obvious, but the major one is that a stick hitting a stationary ball is just like a rolling ball hitting a cushion. There is also the assumption that cushions don't deform much.
Of course a simple experiment shows immediately that this "Theory of 70%" for cushions is totally bogus and you get screwy angles and very poor rebound if you actually move the cushion to be that high. Most cushions are more like 62% of the height of the ball.
The problem with the "Wrist Flip Theory" is that unlike the "Theory of 70%" it is more or less impossible to test. About all you can be sure of is that the flipper believes strongly that this technique is valuable. Even if you point out all the champions that don't use it but still get amazing spin, the question remains: how much better would they spin the ball if only they could learn to flip their wrists?
On the other hand, top players have good sensitivity to how things should work and so can detect when things aren't going quite right. Their observations can be very useful for figuring out why the accepted theories are not complete or correct. For example, Joe Davis pointed out long before many accepted it that contact-induced throw was important to most shots. Joe saw the shots clearly enough that he could notice the effect. Some players still deny CIT, evidently because they can't observe as well as Joe even though Joe had only one working eye.
Given Joe's input, the open-minded physics guy (of the 1940s) would soon have had an experiment set up to measure the effect. And of course Joe was right. In that particular case it would be easy to conduct the experiment and to work out the theory which is pretty simple once you know about the observed phenomenon.
A really bright physics guy would have figured out the possibility of CIT without Joe's input and would have measured the relevant material property (ball-to-ball coefficient of friction) prior to any report from the field. He might even have found out during the experiment that the friction varies with the speed and force of the contact although simple theory says it's constant.