KJP, I just ordered the book (unfortunately our library doesn't carry it, but it looks worth a few bucks for a used copy). Thanks for the rec!
Yes, I would agree that he's figured out he can get out of school for misbehaving. At the least he gets sent home for the rest of the day, at "best" he gets suspended and gets to miss an entire day. Clever kid.

Extreme stress might be at least part of the answer. My husband believes he would have been classified as EG as a kid, so if our son is anything like him (and gosh knows they seem awfully similar!), I can see him being bored crazy in 2nd grade. He also has very few friends, so lunchtime/recess is probably not too fun. I desperately wish he would communicate better so we knew what, if anything, was bothering him.
Right now E is on a gluten-free diet. He was off for a few weeks at the beginning of January, but it seemed like his behavior at school got worse and worse, so we put him back on it. That resulted in an improvement in behavior, but now we're back to weird infantile stuff again. (Maybe he found my stash of Thin Mints in the freezer!)