Just because you can think it doesn't make it true. Snarky responses such as those made are based upon the false premise that the gun is the answer for all situations.
Proper training in a variety of contexts is essential. You can pretend all you want, but the fact of the matter is, people will drop to their lowest level of training under such situations. If a person has been practicing incorrectly, then odds are they will use that deviant method rather than the correct one. Every time I draw my J-Frame from my Nemesis, I put my thumb over the hammer. I do not deviate from this even with a 442. The J-Frame is not my primary gun, but it's essential to practice with it.
It (putting your thumb over the hammer), may not work for you if you have been jumped and beaten to the ground, stomped as you are fighting to get your pocket revolver out.
As mentioned before, this assumes that the solution is to go to the gun. The actual solution is demonstrated in SouthNarc's ECQC course. Take it and find out just how fast these things end up on the ground. You will learn how to reduce the odds of being knocked down and what to do if you are knocked down.