Bud you are lucky, I was caught once even i stop for 21 months. Not all top 3 get tested. it all depend, if Mr Pual want you. He will test you even you are last placing in any of the IBBF!
We are talking about powerlifting.
They test the top 3 or a percentage of the top lifters.
VERY rarely will they test some random guy, usually only if he is unknown and puts up huge numbers.
i've judged in several feds, i know the drill.