Regardless if a child bites or not, I feel it is completely wrong to discipline a child by doing the very same thing to them that he/she did.
My approach to the biting problem is to remove the child to a room where the parent and child are alone, and calmly explain that what he/she did was completely unacceptable behaviour.
They must focus on the parents... eye to eye contact. Don't scream... Explain in great specific detail how & why and what they have done wrong. Ask lots of questions of your child and stay calm. Make sure that you are in charge at all times.
Once you feel the lecture is over, take your child to a corner in your home and have them kneel with their nose in against the corner with no talking or responding for 5 minutes maximum. Then ask them to come see you and ask them "Do you understand why you had to sit in the corner?"
Then have your child apologise to the person whom she/he bit. And warn he/she of the consequences if it were to ever happen again.
I think you will find this method effective with more than just biting.
Good luck, I hope this helps. After all, as the ol' saying goes: Raising children doesn't come with a book.