£1k bets and left a £100+ tip for successful payout? Dodgy customer, probably money laundering, probably known to centralised security services. Will have been identified after that first payout.
£100 tip is a red flag.
It's not about not wanting to pay him out, £12000 is chump change, facilitating money laundering
will get you shut down.
My personal feeling on those bets going back to when I was managing a high street bookies: I wouldn't have toaken the bets in the first place.
Funnily enough... I'd have told them to **** off to Hills
.