Its actually a 1 in 19 chance of a double failure when making 2 attempts on something, but more noticeable because you have a 1 in 10 chance of failing the second time after you have already failed once. Saying its a 99% chance is a common error.
Rolling 2d10 and getting 0,0 is a 1 in 100 chance.
Rerolling a d10 when you get a 0 on the first roll gives you a 1 in 19 chance of the final number being 0.