What process involving bitcoin can be used to create a false explanation for the receipt of a large sum of cash? If the original source of the cash was illegal, how can that process involving bitcoin hide the illegal source and create a legal explanation for the funds?
Ok, I see now.
Bitcoin wasn't built for the purpose of money laundering. It has properties that put it at a disadvantage for use in money laundering (e.g., all transactions in the blockchain are traceable by the public).
But if someone were to use the properties of bitcoin to their advantage, that too is likely possible. Let's say a party's books show artwork that was sold for $10K of cash. However the value of the artwork was really only $2K and the buyer received bitcoins from the seller, as part of the deal, worth $8K. It would be hard for any external party to know the actual value of the artwork, and the $10K transaction might then be left unchallenged -- especially as the bitcoins could have been sent anonymously.
But just like with cash transactions, there are two or more parties involved, and there are clues that will reveal intentions -- especially when larger amounts are involved. Bitcoin probably doesn't change things much. The fact that no bitcoins stolen during the hackings or wallet thefts so far is likely due to no concentrated efforts occurring to actually catch the perpetrators.