Marie can't prove anything, that confession doesn't mean much if the rest of the DEA/a lawyer weren't involved. And we know how obsessed Hank was with this investigation. Taping that confession for a pair of rogue cops out for vengeance won't hold up. and given what we now know about walt and the nature of his relationship w/ jesse, the majority of it can be sold as manipulation. not saying that would hold up in court but it could be his story, and it wouldn't even be a lie.

the money is trickier, but that investigation seemed like a dead end for the local police. of course the DEA could catch wind of it and it's a different story, but i still think walt's manipulation is a strong case.