Duplication While Piston Pushing a chest

This has to be a duplicated issue! but I searched all over for the report. So to be safe here it is.

 

So In a realms survival world I had a player who has been recently banned perform this Duplication glitch where you quickly grab items out of a chest the second a chest is being pushed. This is obviously a popular Duplication glitch because Skippy 6 gaming made a tutorial on how to use it.

 

Here is a step by step tutorial on how to perform the duplication. 

https://www.youtube.com/watch?v=WflwSSkLU1c

 

Lol I hope I am not the first to report this! and ruin everyones fun!