But earlier you said we need more people like her husband and good for him?
Yes, people prepared to act impulsively, let their hair down, and do random things they can't necessarily explain.
So you don't seem to think that sort of behaviour towards staff is unacceptable
Of course abusing staff is unacceptable, I've never suggested otherwise, merely that if you work in retail for long enough you get inured to abusive members of the public, and that what OP's DH did would be a source of bemusement rather than upset in the grander scheme of things.
See what @sweeneytoddsrazor posted. Pretty much the same sentiment from another experienced retail worker.
Sure you might find it 'amusing' to see infantile behaviour others dont. Nor does it mean people have sticks up their arses. Who in this scenario had a stick up their arse?
Nobody. But having dealt with the general public, a large proportion of them do. Typically the sort who march into the premises, purple with rage, ranting and raving, hurling abuse, and STILL expect you to assist them. If those folk with the gigantic sticks up their arses merely V'd and ran away, it would be a blessing.