Shinysides his routine is fine, you have no clue what you're talking about. As long as the muscle being trained to failure has a proper recovery time before he works it out again he should be alright. I also work out 3 times a week to muscular failure and have seen great gains, faster than I did when I was doing a more moderate workout. I do:

Day 1 - Legs/Abs
Day 2 - Back/Shoulders/Triceps
Day 3 - Chest/Biceps/Forearm

His routine isn't the problem, unless he's not following it correctly.