I took an overnight bus from Butterworth to Singapore many years ago and they dumped me at the side of the road somewhere. At that exact moment I had a sudden need to drop the transmission so I hightailed to the nearest shopping mall.
Much to my dismay the toilet was manned by an old Chinese dragon lady who wouldn't let me in because I didn't have any Singapore money. Fortunately her kindly old husband took pity on me and waved me through. Of course, there are no squirty bum guns or buckets of water in that fine city and free toilet paper seems to be anathema to them so I had to go back out and throw myself on the old guy's mercy. The dragon was livid when he handed me a few tiny squares of TP.
Another time I was at a public toilet near the Tanah Merah Ferry Terminal and I was suffering from the local version of Bali belly so it was taking a while. Again, no facilities to clean oneself but I had come prepared after my previous traumatic experience 😂
Imagine my horror when the computer had decided that I'd taken too much time and flushed the toilet whilst I was still doing my business. I'm surprised an alarm didn't go off as well, or maybe send a signal to the local cop shop.
So I'm not at all surprised that this Thai fella couldn't find a "legal" place to take a whizz in Singapore. That place is barbaric when it comes to toilet facilities, despite the outward appearance of sophistication. God help us if Thailand follows suit (as seems to be happening in a few places in Bangkok).