WHEN DID MY CHILD GET SMARTER THAN ME???

Ok, how do I explain what just happened? I guess some background first. My son Zachary woke up sick on friday morning at 2am, he has a barky cough (croup?) and a non-stop runny nose. I sat up with him the rest of the night, but I did send him to school (read past logs and you will know why). He again was up last night sitting on the couch with me watching endless spongebob, which is ok because if you know me well, you know I am a spongebob fanatic... really! Ask me anything, I can answer it. Anyways, I digress. So, of course this morning he is still wide awake and I am crabby from 5 years of no sleep. We decide while dad is out that we will make cookies and then play santa. Playing santa means that I write a long list of toys I want, and they get out all the toys we just cleaned up and put them by the fire place while I pretend to be asleep and then vice-versa. Anyways, the boys decided to start fighting, after untangling kicking legs and punching arms, I tell them to both go sit down on seperate couches. Danny is really good at taking his punishment, except for the fact that he gets the "boo-boo" face and makes you feel like you are taking away his puppy, Zach is another story. He has never once taken a punishment well, there s no punishment that I have found that works on him. So, I hold him down on my lap and somehow he slips though and in the scuddle his arm comes out of his shirt, so I grab the shirt arm and pull on him, which of course makes the shirt pull against his neck. Do you know what he said to me? "if you hurt my neck and I end up in the hospital, I'm gonna tell them you did it." WHAT???? Did he just say what I think he said? I let go of his shirt, he put it back on and I had to walk away. I did not know whether to laugh or be afraid, very, afraid.
When did my 4 year old get so smart? How does that little mind come up with such a statement? Oh, well... if I end up in jail, don't bail me out for a couple days... vacation!
Go Bears.