crafting glitch

when in game (survival) if you take 2 items and craft them together for example diamond picks you craft them in your head (not sure if it maters were) but when taking the item out when crafting it does not consume the 2 picks it leaves them so now instead of having 1 pick you have 3

I do not know if this will happen on a 1.8 server but its possible because its happening with the client