In pubs/restaurants, it seems you aren't hugely likely so infect random other patrons, but you would be likely to infect people you are with.
Incidentally, looking at the odd report from other countries, the British population clearly don't have any kind of monopoly on irresponsibility
The spokesman mentioned a group of Thais who returned Friday night to Suvarnabhumi Airport and refused to submit to government-mandated quarantine.
Of 158 returnees, 152 ‘escaped’ from the airport after refusing to cooperate.
“The Prime Minister is not happy that this incident happened at the airport and we are working to ensure it does not happen again,” said Dr Taweesin.
“Because we have not received your cooperation, we must now go out and find you. All 152 returnees last night must come back under state quarantine,” he said. “You have put your parents and families at risk by returning home. If you do not submit to quarantine, you will face the consequences under the law.”
At least our numbers showed a fall in infections today. Time will tell if that's a trend or just a blip.