Keeping items with /clear glitch

NOTE: I have tested this on multiplayer and it works identically, The screenshots are from singleplayer to show the bug more clearly(The command block is set to "/clear XxDuelistGuyxX". I wasnt entirely sure if this was enough of an exploit to be private, but I figured it could lead to bad things if someone knew about it.

What I expected to happen was...:
The /clear command activates, erasing all items from my inventory, even if I have them selected.

What actually happened was...:
The /clear command clears all the items in my inventory, but It doesnt clear the item(s) I have selected(In this case, it erased the 64 TNT but not the diamond horse saddle)

Steps to Reproduce:
1. Set a command block with a delay with the command set to "/clear (Player Name)
2.) Activate redstone line.
3.) Select item as though you were about to craft with it
4.) Command activates and you still have the item.

This can be exploited if an op needs to clear your inventory or if a map requires it, which is why I made this private.