The Queen has 'Sovereign Immunity' and is above the law. She cannot be arrested/prosecuted or sued because the courts technically belong to her.
The rest of the royals are subject to the law just as anyone else is, although they cannot be arrested in the Queen's presence or in any Palace buildings or property.
Royals have been prosecuted in recent years. Princess Anne pleaded guilty to owning a dangerous dog and she and her daughter have been fined for speeding.
The FBI want to interview Prince Andrew over his friendship with Epstein. He says he will co-operate but has made no effort to do so.
He will not be extradited as he has not been formally accused of a criminal offence abroad, though that looks about to change, and cannot be ordered to be interviewed by the FBI while he is in Britain.
He could talk to them voluntarily in Britain, in Buckingham Palace itself with the corgis as witnesses, but he's not having any of THAT.
Should he want to, Mummy will have put her foot down.
One imagines the Queen could persuade him talk to them but there's too much at stake. He would incriminate himself and goodness knows who else.
Even if there were an international warrant out for Andrew, under British law he can evade arrest by staying in a palace as mentioned above.
The FBI would have to camp outside Balmoral and hope he gets bored and pops out. He is stupid enough to do that.
As it stands, he is showing no inclination to fight to clear his name and is probably hoping it all blows over.
The civil case could take years to come to court.
Ms Guiffre may have to be content with knowing that Andrew will be sweating for all that time, especially when the Maxwell trial/mysterious Maxwell death is in the news.
The FBI and the royal family are aware of all this and the upshot, I reckon, is that he will sit it out until 'er Maj kicks the bucket and all hell breaks loose.
This is better than any novel or TV series.