A funny Charlieism

On Thursdays I watch my friend Emily's two boys, aged very closely to my two, while she runs errands with her mother. So for about two hours, I am fully responsible for FIVE kids, the oldest of which is three.
Anyhow, generally the 4 boys play well together and keep each other well occupied, so sometimes it's even to my benefit. HOWEVER, there are also many small spats about who wants which train, who gets to go first, who did blah blah blah. So when I was making lunch and heard a bloody murder scream erupt from the playroom, I though for sure it was a scream of injustice and ran to see what was going on, a little annoyed at the perpetrator. When I got there Sam was crying hysterically and holding his left hand. I asked what happened, but he was crying too hard to speak. I asked the other boys what happened, and no one seemed to know. Upon inspecting Sam's hand, I saw that not only was there a complete bite mark on his finger, but also that the skin was actually broken. I demanded to know who bit Sam but no one fessed up. Sam finally snuffled through his sobs that it was "chawee" and I asked Charlie directly. He finally confessed and I took him to time out and told him to sit there until I came back. (As a side note, he did not cry or complain at all in time out, in broad contrast to my own kids who cry like it's the end of the world and often even yell things like "nobody doesn't wuv me anymore", and I guess it may have had to do with my calm sweetness because I was dealing with someone else's kid). When I called him out of time out, I told him we don't bite people and that it hurts. I showed him Sam's hand and told him to say sorry to Sam. He looked at me and said "Do you wanna know WHY I ate his finger?"
I nearly started laughing, but maintained my composure and asked why. He said "Because he knocked over my train so I ate his finger." I explained that no matter what happens, it's not okay to bite and we don't ever eat anyone's fingers.
Aaah, add that to the list of things I never thought I'd have to say...