We have a 10 year old Lab and currently a 7 month old Lab. I am pleased with how well he plays with out current puppy and 3 others we have had since he came into our care 2 years ago. However many dogs by the time they are that old want nothing to do with puppy biting games.
Young Labs, which I know best, and other puppies tend to very bad about biting. You see a litter of them, and all the ones that are awake are biting another one or themselves. I am not even sure they realize that when they are alone, if they quit biting, they would quit being bitten.
I don't see the behavior I described above in Spezza at all. It could be sometime in the past a young child was allowed to abuse him or even a lack of early socialization to children. A good trainer should be able to recognize what is really happening and suggest positive methods to correct it. The older the dog, the more difficult to change behavior, but it can be done.