Condoms and water check method

Anytime my boyfriend and I use condoms he checks for holes by filling it up with water when we’re finished. I’ve heard people post on here about getting pregnant with “microscopic tears and holes in the condom.” So if that were to happen would I not be able to see the break with the water check?

Even tho he pulls out 80% of the time I’m just curious Bc I don’t understand.