I would say your friend is either very ignorant or very lazy!
There are a variety of excellent responses to your question here and your friend needs to read them. I don't mean to sound harsh but from what you've said it seems to me your friend is either totally unaware of what dogs need, in which case he/she shouldn't have a pet or worse still, your friend may be just plain lazy and wants to take the 'easy' way out, for him. Its not the easy way, the compassionate way or the right way for the poor puppy.
Using a shock collar is simply cruel punishment for something the puppy will naturally do. The puppy is probably teething, and just like a human baby it will need something to ease the pain of new teeth trying to push through, but even so, dogs chew no matter what their age, thats just a part of being a dog. DO you think shock collars would be allowed on any other animal? Here in Australia someone using such a collar could be in trouble with the RSPCA.
Perhaps your friend shouldn't own a dog at all, or at least, wait until they acquire some knowledge about dogs. Ask your friend how he/she would respond to shocking as a means of learning. Ask him if he would like to be shocked every time he did something HE DIDN'T KNOW WAS WRONG. Ask him if thats a way he would like to learn a new behaviour, and when he says no, ask how he could learn something new, and then apply some if not all of that knowledge to how he/she treats the puppy. Theres not a huge amount of difference in basic conditioning between humans and animal babies.
Shocking an animal is purely and simply appalling cruelty and will create serious behavioural problems further down the track. The dog will be frightened of many things, including its owner, who should be more than that, they should be its carer too. Read the posts by RubyRoo and Bill. I sure hope you can convince him/her to listen to the people on the forum here because I feel deeply sorry for that poor puppy.