Shift-clicking crafted items increase achievement objective by 2

I'm pretty sure this is a global error which will occur with all worlds in 1.8

The scoreboard objectives:
achievement.buildPickaxe
achievement.buildSword
achievement.buildHoe
achievement.buildWorkBench
achievement.makeBread
achievement.buildFurnace
achievement.buildBetterPickaxe
and
achievement.bakeCake
all receive 2 points when a new wooden pick, sword, or hoe etc. is crafted. (Edit: I found out in 1.8.1-pre2 that this only happens when you SHIFT-CLICK the item after it has been crafted, it works properly if you just drag it out of the finished crafting square to your inventory.)
I have tested several times with all command block contraptions turned off.
There may be other achievements which also do this, these are the only ones I have found. It seems like it's all of the crafting ones.
Thanks!
-Pecola1