To have not helped this man ?

[RoxyMoosic]

In Morrison’s this evening, and i’m paying for shopping at one of those self-checkout tills - the long version for trolleys (only because no actual tills were open ) The man at the one next to me comes over and says that his card has been declined and could I pay for his roughly £20 worth of shopping. He said he would bank transfer me. After thinking about it momentarily, I politely told him no, as i wasn’t keen on giving out my bank details to strangers. Plus, I didn’t understand how if his card had been rejected it would allow him to transfer me the money there and then anyway. Thinking about it , if it had been someone elderly , or another woman i probably would have helped out, but he was a young dodgy-looking guy and i couldn’t help thinking the way he asked me sounded a bit strange.
AIBU?

I wouldn't have helped either. How can he send a bank transfer if his bank card doesn't work due to lack of funds. I'm sure he was not about to drop down dead from lack of the items he was trying to buy. TBH I wouldn't have helped anyone who did this - I have a suspicious mind and would assume it was a scam. (Well, I might give someone a few coins if they were paying cash and didn't quite have enough...maybe, if they looked trustworthy or deserving.)

If I had it spare I would have paid for it with cash as a good deed but I'd never give anyone my bank details for a transfer, Yanbu.

It's a double scam one get some money off you two steal your bank details.

The bank details someone needs to transfer you money won't allow them to access your money.

You did the right thing though, he was probably trying his luck and no doubt had no money in his account which was why his card was declined and he was hoping you'd pay and he'd disappear and you'd never see the money again.