Bug in BrewEvent? or am i missing something?

Craftbukkit build #2449

What this code does is it prevents players from brewing potion of invisibility by converting those potions to Mundane Potion on the BrewEvent.

PHP:

    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
    public void AntiInvis(BrewEvent e) {
        BrewerInventory i = e.getContents();
        if(i == null) return;
        if(i.getItem(3) != null && i.getItem(3).getType() == Material.FERMENTED_SPIDER_EYE){
            if(i.getItem(3).getAmount() > 1)
                i.getItem(3).setAmount(i.getItem(3).getAmount() - 1);
            else
                i.removeItem(i.getItem(3));
            for(int k = 0; k < 3; k++){
                ItemStack item = i.getItem(k);
                if(item == null) continue;
                if(item.getType() == Material.POTION){
                    if(item.getDurability() == 16310 ||
                        item.getDurability() == 16374 ||
                        item.getDurability() == 32694 ||
                        item.getDurability() == 32758 ||
                        item.getDurability() == 16318 ||
                        item.getDurability() == 16382 ||
                        item.getDurability() == 32702 ||
                        item.getDurability() == 32766
                      )    {
                            e.setCancelled(true); // Needed to stop mundane potions from turning into potion of weakness
                            item.setDurability((short)8192);  // Sets it to mundane potion
                        }
                }
            }
        }
    }

Code:

    06:10:21 [SEVERE] java.lang.NullPointerException
    06:10:21 [SEVERE]  at net.minecraft.server.TileEntityBrewingStand.t(TileEntityBrewingStand.java:155)
    06:10:21 [SEVERE]  at net.minecraft.server.TileEntityBrewingStand.g(TileEntityBrewingStand.java:57)
    06:10:21 [SEVERE]  at net.minecraft.server.World.tickEntities(World.java:1292)
    06:10:21 [SEVERE]  at net.minecraft.server.WorldServer.tickEntities(WorldServer.java:458)
    06:10:21 [SEVERE]  at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:558)
    06:10:21 [SEVERE]  at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:215)
    06:10:21 [SEVERE]  at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:487)
    06:10:21 [SEVERE]  at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:419)
    06:10:21 [SEVERE]  at net.minecraft.server.ThreadServerApplication.run(SourceFile:818)
    06:10:21 [SEVERE] Encountered an unexpected exception NullPointerException
    java.lang.NullPointerException
    at net.minecraft.server.TileEntityBrewingStand.t(TileEntityBrewingStand.java:155)
    at net.minecraft.server.TileEntityBrewingStand.g(TileEntityBrewingStand.java:57)
    at net.minecraft.server.World.tickEntities(World.java:1292)
    at net.minecraft.server.WorldServer.tickEntities(WorldServer.java:458)
    at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:558)
    at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:215)
    at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:487)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:419)
    at net.minecraft.server.ThreadServerApplication.run(SourceFile:818)

:::UPDATE:::
Just read for the 2nd time http://wiki.bukkit.org/Event_API_Reference#Event_Priorities