Nick,

This is from an article I found somewhere

The ranking stage: Three to six months

• Ranking (dominance and submission) within the household or "pack," including people, is seen and used by a puppy in this stage.
• A puppy's play group, which may now include those of other species, becomes influential in his or her life.
• Teething and chewing begins.
• A puppy experiences another fear stage at four months of age, so be prepared with positive reinforcement and introductions to objects and situations.

The adolescence stage: Six to eighteen months

• A puppy is most affected by human and dog "pack" members.
• A puppy may challenge people as part of exploring his or her dominance in the "pack."
• At seven to nine months, a puppy will begin exploring more of his or her territory, prompting a second chewing phase.
• A puppy will experience the beginnings of sexual behavior if not spayed or neutered.

What we probably going on here is an ill informed "trainer" treating the CC like it was a toy lapdog. That is the reason I do not let anyone play with my dogs or train them.  Most trainers do not understand guardian dogs and what drives them, even at a young age.

Not sure this can be really fixed, but the owners must take control of the situation and exert influence over their dog.  They should not pass that duty on to someone trying to make a $ as a trainer.