I guess I'm still a bit lost as to how the money proves he's Hisenberg. They have Jesse's confession, but he's a junkie so he may not be the most credible witness. Jesse wasn't even party to the activities that produced that money, so he can't connect Walter to it. All Saul's guy can testify to is having seen the money and providing transport, but given that he could be an accessory after the fact if he pleads the Fifth that's kind of a waste. Walt being at the site of the money connects him to the money, provided they find it, which gets him for tax evasion. I must be missing something, because I don't see how the money puts him on the hook specifically for meth dealing.
Maybe if Hank had recorded the conversation that Walt and Jesse had where Walt admits to a bunch of murders he'd have something better than tax evasion, but there's nothing to suggest right now that he did.