Samourai’s lawyers had claimed that the call showed Rodriguez and Hill “were not money transmitters under FinCEN’s guidance” and that they “could not possibly be prosecuted for not having a license.”

The Samourai co-founders had bid to dismiss the case in April, pointing to Deputy Attorney General Todd Blanche’s memo released that month saying the Justice Department wouldn’t prosecute crypto mixers for “unwitting violations of regulations.” 

In their letter, prosecutors addressed the memo, arguing the court “should not consider” it, as the memo states it “may not be relied upon to create any right or benefit” against the US or its departments.