I remember this issue from when I was living there and had a running list of reported dodgy products.
Bubble Tea: Tapioca balls substituted with plastic (blamed on China)
Chilli sauce: Orange lead paint added for colour
Coffee: Actually some kind of sump oil with caffeine and coffee flavour added
Fried shallots: In reality bits of sweet potato
Meanwhile you couldn't go to a backpacker bar without some idiot tourist convinced their hamburger "was actually definitely dog". Dog meat typically costs far more, of course.