IANAL but this argument doesn't seem to be on firm footing due to the extradition laws on the books. Technically I can violate a UK law while in the US and indeed be subject to their jurisdiction.
That's not really relevant though. Being a UK citizen and breaking a UK law while on US soil (where the US doesn't have a similar law), and then seeing consequences for it when you return to the UK doesn't change anything.
If a UK person is on US soil and breaks a US law, they will be prosecuted by the US. The US can choose to extradite to the UK, but that's not really relevant.
If you care to read some cases, this link is informative https://hansard.parliament.uk/Commons/2020-01-23/debates/B8A.... You don’t have to be on “soil” to break these laws. The US certainly extradites loads of people from other countries who still reside there and only broke laws either “online” or through transactions involving the US
> The US certainly extradites loads of people from other countries who still reside there and only broke laws either “online” or through transactions involving the US
This further weakens the dishonest posture that tourists are not subject to US law
If a UK person is on US soil and breaks a US law, they will be prosecuted by the US. The US can choose to extradite to the UK, but that's not really relevant.