I've got a whole mess of issues and ADHD is just one of them. I can say yes it can be part of it however it is not an excuse. I've had anger issues my whole life and yes I used to be very much like what you described but as a child. I've since learned to control my temper for the most part but still have my moments.

If you decide you want to take it head on then a few things to remember.
1. Try not to put him on the defensive if you can help it, it will only set off a trigger
2. Keep as calm as you can, don't speak to him like a child but keep calm.
3. If it starts to get heated then let him know you can finish the conversion later if he wants.
4. Having someone else around, an adult, but not in the same room can help keep him defused in a sense.

I'm still rather new to the groups here but hopefully this offers some amount of help for ya. Best of luck to you.