You seem to have a basic misunderstanding of what was happening here. It had nothing to do with money laundering. Steam was accepting transactions before they

You seem to have a basic misunderstanding of what was happening here. It had nothing to do with money laundering. Steam was accepting transactions before they were confirmed by the bitcoin blockchain. Its like accepting a check and handing over the merchandise before the check clears. It is also why most places don't take checks anymore.