Swords breaking blocks in creative mode

I was going to the End to fight Ender Dragon, I wanted to do that easy, so I gave myself a Sharpness 4000 iron sword.
Accidentaly I pressed left button on a block ad it disappeared without any sound or particle.

Edit: After accessing the End, I quitted from the world for a while and, when I relogged, the sword was disappeared from my inventory.

Edit 2: I re-gave myself the sword through the same command, and it was no longer able to break blocks