While not as important as having a job, etc, it could possibly affect overseas travel. Someone couldn't travel with us from the UK to our wedding in the US as we learnt that anyone who's been arrested for any reason can't travel under the visa waiver program (they can apply for a visa though but that takes time, money, and an interview). And as far as I understand it, US VWP treaties operate on similar principles in both directions.
> We recommend that anyone who have ever been arrested and/or convicted of an offense apply for a visa. In cases where the arrest resulted in a conviction, the individual may be permanently ineligible to receive a visa and in order to travel, a waiver of the permanent ineligibility is required. The Rehabilitation of Offenders Act does not apply to United States visa law. Therefore, even travelers with a spent conviction are required to declare the arrest and/or conviction and apply for a visa.
Imagine you've just spent £X00 on a ticket. Would you gamble that (and the cost of flying back if denied entry), and your future chance of entry to the US, on getting through US border controls?
Sounds like he read the question asked when you go here: https://esta.cbp.dhs.gov/esta/ and apply for the visa waiver. And he didn't feel like forking out for plane flights just to be turned back at the border.
"B) Have you ever been arrested or convicted for an offense or crime involving moral turpitude or a violation related to a controlled substance; or have been arrested or convicted for two or more offenses for which the aggregate sentence to confinement was five years or more; or have been a controlled substance trafficker; or are you seeking entry to engage in criminal or immoral activities?"
