Duplicate items using chest when lagging (On a server, not sure if this works in singleplayer)

By crashing a server with lag you're able to duplicate items by taking them out of chest and then let the game crash with lag (I crashed it accidentaly by having a group of 300+ skeletons from a skeleton farm). When you then start the server again the items you took out of the chest will reappear again. For example I took out a pickaxe and was able to mine with both of them.