What are the implications of the double-slit experiment?

Suppose you have a sink with two holes in it, and you are blindfolded, and you drop a ball into the sink and you can't take the blindfold off until after the ball falls through one of the holes. And then you have to observe the ground to see which hole it went through, because you weren't looking then.

And you find two marks on the ground as if the ball landed twice and went through both holes somehow...

And you say that's impossible so you create a motion sensor on each hole, and only the hole it goes through will light up red with LED lights, and you try it again, but now there is only one hole that is lit up and only one mark on the ground. Like the ball itself changed its behavior and the universe itself changed its rules because it didn't want to contradict with your experiment. But the first time there was nothing to contradict, so it didn't have to follow the same logic the first time.

As if the rules of the universe are dependent and not absolute somehow.