The attorney concedes that the US does not seek reimbursement for rescues for valid policy and legal reasons but then conflates his clients claim to a sought of .. If they change their mind they should not sit around and wait for the money.. It's a waffling argument. What I think he ment to say is that the Kaufmanns are suiting for the loss of their boat and if the USA wishes to join in with them that's ok but in the meantime we are protecting the USA interests by bringing a suit for the rescue costs.
The lawyer framed the argument badly. And I don't think the Kaufmanns have any exposed to the Government so their subrogation claim " just in case" is bad PR and not well thought out.