Another attack - this time strange

Well, all the attacks are strange in their own way but this time it was really strange. I put Kuma in his crate while I went to the rental office to grab some packages. I came home, hung around for about 15 minutes (doing the separation anxiety ignore) and let him out of his crate. When I decided to let him out, he appeared calm and was laying down.

When I let him out, he didn't come out right away which is strange. I watched him - he finally came out and layed down under the dining table but was fairly restless and he was being a bit weird. He hadn't eaten one of the treats I left for him - I wasn't sure what to do about that - I thought maybe he just hadn't had time to eat it since I was only gone for about 5 minutes. I also wasn't sure I wanted to grab it and put it away because he seemed so tense - so I left it. Since he was pacing a bit, I had my back to him a good amount of the time and that was making me nervous. So, I went and sat on the couch while he was laying down under the dining table.

I had been sitting down for about five minutes or so when Kuma came over and jumped up on the couch and sat VERY close to me (which is a sign something is going to go wrong). He's not allowed on the couch unless he's invited so I made him get off by pulling gently on his collar until he jumped off - he didn't put up a fight at this point. Then he attacked me - he bit my hand twice quite hard - left marks but didn't break the skin. I grabbed him by his scruff/collar and put him in his kennel. He fought the entire time and was trying to bite. I put him in his kennel and he stopped - I left him in there for about an hour because I wasn't ready to see how he'd act.

I let him out and put his gentle leader on - he's ok now... but being a little weird still.