It can at times. At one restaurant, now closed in Sunee Plaza, I tipped a guy by putting money in his pocket but also left money in the folder. The Thai woman, wife of the owner, saw this and demanded the waiter give her the money. That was the last time I went there and did my friends.
On the other hand a Thai guy, who I hang, with always says put the tip in the waiter's hand or outside the folder