BTW, he doesn't exactly need a visa, he was on an ESTA.
If he really was banned for life there's more to the story than his inability to prove non-immigrant intent (e.g. fraud, criminal history, etc.). Even people present in the US illegally for extended periods of time are not banned for life.
Edit: Added source. All that is needed is that they believe you lied to a U.S. government official and they can ban you for life.
It can basically be considered fraud if this is true:
> When making the false representation, the person intended to deceive a U.S. government official authorized to act upon the request (generally an immigration or consular officer).
And this is the consequence:
> The person will be barred from admission for the rest of his or her life unless the person qualifies for and is granted a waiver.
https://www.uscis.gov/policy-manual/volume-8-part-j-chapter-...
How can you prove something that didn't happen yet? Best you can do is provide clues and circumstancial evidence but no proof.
It's good that they were being so vigilant! Let's not forget that USA has so much trouble with UK citizens overstaying their visas. /s
But the law is quite clear that anyone applying for admission to the US is presumed to be an intending immigrant and the burden is on them to prove they will leave before their duration of status expires. Literally millions of people per year are denied visitor visas because they can't meet that burden of proof. Not sure why this is particularly newsworthy.