Just read this article. Old Chang Kee apologised twice for a insect in curry puff incident. Getting insects in the food is every food stall's nightmare. If it does happens, the stall will have to be apologetic and take it as their fault since NEA will sure come snooping. Of course there will be the low life consumer that may, in rare cases did something. Or the consumer could be nasty and demand more than just apologies. In any cases, food stalls just need to be humble, if it isn't their fault, they would be cleared by the authorities. Having arrogant staff will just make matters works. Sure that there are shortages or workers but getting that hard to find workers vs getting costumers friendly workers, which one would you prefer?
https://sg.news.yahoo.com/blogs/singaporescene/old-chang-kee-sardine-puff-reveals-nasty-surprise-234710682.html