VIDEO: https://www.youtube.com/watch?v=wZBVcauTZyQ

NOTE: Do not pay attention to the second guy in the video. He was just there. Has nothing to do with the bug

This wierd glitch happened to me when i created this very quick redstone block clock. You will all know how the clock works but in case not, there's one commandblock with this code in it:
/setblock ~0 ~0 ~1 minecraft:redstone_block 0 destroy

I had to record this in 120 FPS because in 30 the glitched stuff wouldn't shhow up in the recording
I can't really say much more...

VIDEO: https://www.youtube.com/watch?v=wZBVcauTZyQ