How do you expect the "pull out" to happen? They must have had a UK bank account or similar, whose transfers won't get approved as they're trying to escape from criminal prosecution. Or they'll work with the US to ensure responsible individuals are held responsible.
It isn't exactly the first time someone/something commits crime in a country then try to escape, there is lots of ways to work with others on this.
I heard here recently during a similar discussion (about 4chan and this same British watchdog agency) that the US does not allow extradition of its citizens for breaking non-US laws if the behavior is legal in the US.
How so? None is needed to take revenue from UK-seen ads.
May US voters put America First over international law.