That's not how I read it, I don't see how one could argue that irreversible transactions are a money laundering tool. Credit card transactions aren't completely reversible either, you have to either claim that the card was stolen or that the merchant didn't deliver. If you charge back routinely, then the card companies are supposed to crack down on you. Though I don't know if that really happens.

I think we should expect the head of FinCEN to argue that more or less anything can be seen as money laundering. She directly and personally profits from expansion of the notion of money laundering. That doesn't mean other people have to agree.

 

I think we need 2-of-3 dispute mediation and have thought that for a long time, indeed, Satoshi's paper says so:

https://en.bitcoin.it/wiki/Contracts#Example_2:_Escrow_and_dispute_mediation

It doesn't require any core protocol changes but it does require deployment of the payment protocol first, as that's the foundation on which we can add lots of other useful features like that. And then it needs a whole lot of work to define how you open a dispute from your wallet, how you find mutually agreeable mediators, etc. Having reversible payments in which one of the trading parties gets to decide whether to reverse seems pointless to me. If the buyer decides it's simply equivalent to post pay, and if the seller decides then it's just a refund, which the payment protocol already supports.