I agree that the ear can be trained. When I started doing sound almost 20 years ago. I couldn't tell the difference between 250 Hz and 400 Hz - After learning the frequencies, I can easily EQ any speaker, by calling the frequency out to someone else who is operating the EQ for me.Reggae Joe:Lessons are good...it'll help him if he has a solid sense of theory and structure (modes, scales, etc.). Make sure to help him keep developing his ear, though...that's something that's crucial.
People may not be able to LEARN perfect pitch, but you can be trained to have great pitch