Because he really kneaded the dough. (please forgive me for that awful pun)
When he found out, Santa shouldn't have gotten mad, he only had his elf to blame. Now Santa won't forgive him until elf freezes over.
I dough know.
Because he kneeded a poo
When it's unnecessary
Because he kneaded a poo.
Because they knead dough.
He didn't knead any more dough.