Harder? Nah, more expensive but not harder. Not for anyone with any kind of money.
Too many ports / docks with no security and too many people with private jets that don't ask questions.
A distinction would be that he'd have frustrated further travel-- could he get out and hunker down? Sure. It would also mean that he'd be vulnerable to an immediate arrest when we did track him down. As is, he's just lawfully jetting around, which is less preferable.
Aside, the house he was renting in the UK is now listed again:
https://search.savills.com/gg/en/property-detail/gbcorecbs170012l