This is simple. Presuming that you have a US credit card, simply do a partial chargeback for the value of the room on the grounds that the property did not provide the service. Then, to the extent that you are helping out your friend, send him those funds.
Presuming that they were on either an EU carrier or that it was the onwards flight to the US that was cancelled, both passengers should be claiming for the room under EC 261/2004 and returning those funds to you in any event.