It's been implied in the story that Calvert (aka Squeaker) DOES still retain his power. Which is good (for Calvert) because his abuse of said power did not help him learn to actually be sneaky. It taught him how to save scum. It's the difference between someone using save states to reload any time they trigger an alarm or get hit by a boss fight during a Metal Gear Solid play through, vs someone who can flawlessly get through Metal Gear Solid without ever getting spotted or hit during boss fights without save scumming. The person who's able to do so without save scumming is far better at the game.
It's why Calvert thought his power made him unbeatable. If a plan didn't work, he could effectively reload to before the plan had been attempted, and theoretically nobody else would ever know what he'd tried to do. A plan fails due to "random chance", he keeps that plan in reserve to try again later. You know, because he'd technically never enacted that plan, so he assumes it's a good plan that just got screwed up via random chance.