It sounds like both of these things happened after his meds wore off. And with ADHD kids, its not unusual for that to happen. And, he is only 7 and might have had a very tiring day, etc. But you wouldn't know that unless, you have been reading up on ADHD. And that is what you can do. Working with an ADHD kid is different. I know - I am the CL on the ADHD forum and have worked with ADHD kids for years, and years, and years.
Here is a starting link dealing with anger and ADHD kids. I think you will find it helpful - http://www.additudemag.com/slideshow/74/slide-1.html
I have lots more info if you are interested. Best wishes.
Thank you for your post. In your case, I as so glad you found a psyc that perhaps was a bit ahead of the rest. Now, (hopefully) it is a bit more common for psyc's to realize that anger is a part of the ADHD. Anyway, a link here that you might find useful or if nothing else validation for what you are doing.
http://www.additudemag.com/adhd/article/7951.html