Simple item troubles

I am always having struggles with my item handling. What I am currently doing is throwing snowballs, but I cancel the event (I am going to set the velocity to a different one) and I can get the hand to empty of snowballs. Once the slot is empty, it is empty.
If I switch my hotbar to another item and right click, the snowball reappears. Here is my code:

Code:java

if (e.getAction() == Action.RIGHT_CLICK_AIR || e.getAction() == Action.RIGHT_CLICK_BLOCK) {
    if (item == Material.SNOW_BALL) {
        e.setCancelled(true);
        p.sendMessage("You cannot throw snowballs!");
        if (hand.getAmount() > 1) {
            hand.setAmount(hand.getAmount() - 1);
            ze.getLogger().info("ASDF");
        } else {
            hand.setType(Material.AIR);
            ze.getLogger().info("FDSA");
        }
    }
}

The messages within there were all debug tests, FDSA is called when there is only one snowball is in a player's hand, which is suppposed to set that item to NULL, but it doesn't really do that well. As I said, if I switch to another item in my hotbar and right click, the item re appears.

 

try calling an inventory update, I had this issue once too. where inventory doesn't update.

 

That doesn't change a thing.