Copper, aha or learning opportunity

I was tired last night and did not put two and two together. I now know why Copper did what he did last night.
Yesterday when I was cleaning, Kevin was sitting in his chair, Copper stole his bluetooth off of the table. I told Kevin he had his bluetooth, and Kevin flew out of his chair and pinned Copper on the couch and took the bluetooth from him. He did growl at the time but was not able to snap.
I was getting up quickly to go to distract Copper, and he felt threatened after the situation earlier.
So Kevin has learned that no matter how precious, what ever Copper has, he needs to give the drop it signal calmly. This morning Copper got hold of my raincoat bag, I calmly gave him the signal, and he dropped it immediately. I have a container of food and rewarded him. He does want to be a good boy, just does not take pressure well.