> the British don't need a visa to come to America as tourists.

They require a visa OR a visa equivalent.

  To enter or transit through the US, you must have either an Electronic System for Travel Authorisation (ESTA) OR a visa.

GOV.UK travel advice to UK nationals seeking US entry. https://www.gov.uk/foreign-travel-advice/usa/entry-requireme...

The woman having a visa is common and doesn't negate the tale told.

A US visa is typically for entering only. It doesnt say anything about the duration of stay. The latter is determined by CBP at the port of entrance and printed on your I-94. This is never emphasized anywhere.