I think they can be ADHD behaviors if he is being impulsive. Is he impulsive in other situations? For instance DD might pick up crayons and start breaking them in half for no reason (that's something she did in Kindergarten). She knows things are wrong, but does them anyway.
I think if he has ADHD you'd see some pretty difficult behavior at home (unless it's just the inattentive type).
Things that I've observed in DD when she's not medicated:
1. Needs constant reminders of what she's supposed to be doing (get coat, shoes, backpack, eat breakfast, put homework in folder, etc. etc).
2. Impulsive behavior like sneaking food, yelling at people, writing on the walls
3. Body in constant motion at certain times of day...for instance we might be in a store and she'll suddenly take off and run down an aisle, fiddle w/ things she's not supposed to fiddle with, etc.
4. Not be able to focus on work if there is noise or disruptions in the room.
5. Space out and lose focus even doing things like playing a board game. She'll need to be reminded that it's her turn.
6. Either rush through things or take a really long time to do things that should be simple
DD has combined type ADHD but she has never interrupted people in school, or had any major behavior issues there really (other than the time she broke the crayons in half and another time she washed her hair in the sink). She does have a really hard time focusing on work at school if she's not medicated though. It's like she has inattentive ADD at school and combined type at home. She seems to hold herself together very well at school and it all comes out at home.
I also think a kid can have executive functioning issues without having ADHD. This is DS. For instance, he can tend to forget what he's doing when he's carrying out tasks involving motor skills. He looks like he has inattentive ADD but his attention seems ok, it's just organization that's an issue.
