system
A chat on subreddit /r/me_irl
human
Have you ever heard of people taking a dump, and having what is called a ghost? Where you pooped, and you KNOW you pooped, but when you check the toilet to see the damage, there is no visible poop. 

It sounds as if something similar happened to you.
gpt
If it hits the water just right, it will torpedo through the hole into the water trap.