He was not asleep at the times this happened, just resting and even touching me with parts of his body.
He is a healthy one year old. So there is really no medical explaination for this either.
Are you sure? Was it only a snark, or any hint at all that he has an "ouch" somewhere? I have had two overly sensitive Basenjis that would snark or even nip if they were hurting…....or protecting an area of their body that had been hurt. Sore muscle or whatever. In my case I knew, because a yipe preceded the snark. The other possibility was that he was comfortable and didn't want to be moved. There's no excuse for snarking for that, and it should never be tolerated, although I like to be diplomatic and not provoke it in the first place if I can. However, once it happens the last thing you want to do is let him back you off.......a mistake made all too often. It's great positive reinforcement for them to do it again.
My own personal reaction to a snark or a nip is to restrain the dog until he quits it, (bear hug or whatever), all the while informing him verbally of his sins. Once he settles down, I will offer my hand or arm and essentially dare him to consider a nip. ("go ahead, make my day!") This is not everyone's preferred method, but it has worked for me with both dogs and horses over many years. Do not attempt if you are not confident, because the animal will know it immediately! I agree that banishment from the couch is a good idea. (no, my horses are not allowed on the couch!)
Another thing I like to do after any major misbehaviour is "doggie pushups". Sit, down, sit, down. If complied with, this earns "good dog" and an opportunity for him to be back in my "good books".
Edited to add I have never had to resort to any long term banishment from the comfy couch, but this type of incident has been exceedingly rare for me, and seldom repeated. Just lucky, I guess.