Many Thai businesses have exterior tile floors. Some sandals have soles that give almost no wet traction on smooth tile. I’ve seen some hard falls where the person’s foot went out from under them on their first or second step onto the wet surface.
Still on the same subject, though I didn’t know it at the time. I was conversing with a foreigner resident about Cricket (really) when one of us mentioned that it looked like rain soon. He said his Thai wife had predicted rain that morning by not letting him out of the house in his favorite sandals. The slippery ones.