swimming on land

While playing my first 1.14 survival world, i encountered a glitch that could possibly be used as an exploit 

As you can see in the included picture below, the player starts the swimming animation, and behaves like it is swimming, but on land

this happens when you stand in a fence post 1 block above the ground and then close it

i have tried, and yes, you can go through 1 block high holes with this

this works in all gamemodes except spectator, and in both single and multiplayer (including realms)