How does one "accidentally" do that?

Scene:

We're at the school playground. Elliott approaches me and tugs at my arm. "Mommy? Can I tell you a secret?"

He goes on to say, "I accidentally bit J. I am sorry. I didn't mean to."

Maybe 15 minutes later, after a chat and apology, S says, "he bit me and hit me, too."

WHAT?!?!

How does a 5-and-a-half year old ACCIDENTALLY bite someone?! Twice? WTF?

Elliott is spending some quality time in his bedroom right now.