@grips I mean you don't wait around or anything, but technically that's what's going on, the tap water is closer from the tap to the temperature of the eggs than warm water.
The temperature differential is what breaks the shell, from my understanding.
I boil a lot of eggs and have no trouble with this method.

N.B. You should not boil warm water from the tap especially if you have metal pipes, as the hot water line will naturally have more junk dissolved in it.