Earlier quoted context omitted.
So what you're saying is that their compliance and risk teams are on top of their game? Kava is illegal/regulated in Europe and the UK and therefore the money and account would obviously be frozen pending an investigation.
Neither the sender or receiver had ever stepped foot in Europe or the UK and had anything to do with those jurisdictions. Go read the Acceptable Usage Policy... nowhere in it will you find anything about every customer being subject to UK law. In fact they go out of their way to make you think the opposite is true... by showing you different AUP's depending on which country you're in.
UK law on kava (and many other drugs) is stupid, but that's not TransferWise's fault.