It's not clear to me who the conference is supposed to involve, so I wouldn't jump to any conclusions. Then again, I don't know how the handbook is written so those definitions may have been covered.
My main concern would be the overall lack of communication, both with regards to his general behavior and this specific incident. I don't know that I would have expected a call during the actual event, but I would expect a little something more than just a note that could get lost in the shuffle. A phone call or email would be my expectation.
Sadly, I have learned that no news doesn't equal good news when it comes to communication.
Things have to get really bad for most teachers to take the time to tell parents. IME, you have to be proactive and "touch base" on a regular basis to make sure things are going smoothly and help to smooth things out before they spiral into something worse.
I know the frustration of having a child with a diagnosed disorder that isn't severe enough to warrant an IEP (yet), because the child isn't just failing. We are stuck between a rock and a hard place. Do we just stand back and let our child fail because only then will they be "protected" by an IEP? Or are we proactive and stay on top of them by supporting them the way we know they need to be supported?
ETA: My instinct would be for him to only be given credit for the words that he personally spelled on the test and automatically counting off the three words that he copied. It seems like that would be actually fair, make sure that his goal of getting an A didn't happen as a result of his actions, and demonstrate that tests are about showing what you actually know.