It happen in multiplayer / creative mode.
My friend was the hoster of the dedicated server. I witnessed the scene in live cause I was watching just behind when it happened. He started some modifications following a misunderstanding, I told him to go back. So he did a strange sequence which I'm not really sure.
I can only assume it involved the undo and redo button for sure and maybe put a blocks line. It was like if the both were processed in same times and have caused the destruction of the blocks. When he did the redo the blocks appeared but instantly exploded.
{F6584}
Here the logs :
{F6587} {F6586} {F6588} {F6591} {F6590} {F6589}
{F6592} {F6594} {F6595} {F6593}
{F6596} {F6597}