Re: What else
I suspect that what happened was that the image was published with global permissions, and it popped up in his feed randomly. It probably looked to him like someone playing dress-up as a Northern Irish paramilitary.
My guess is that he took a screenshot but not a link, buggering up the opportunity for further investigation and realising what a ninny he was making of himself.
But once they started questioning the guy, they really should have dropped it, because it's clearly all very silly.
Nightmare for the guy in the pics, though; poor sod.