There is not just one right way to lift a weight. All tempos serve a purpose and can be used at different times in different programs. Slow eccentrics are excellent for new lifters (to help teach correct technique) and for hypertrophy programs. In many strength programs you will see faster eccentrics because you can get more explosion out of the strength shortening cycle. A slow concentric in this case may simply be a factor of a heavy load.
I'm not saying your friend was making a good decision. Maybe he was or maybe he just doesn't know what he's doing. I just wanted to clarify that a 311 tempo is not the end-all-be-all of training.
Ian King wrote an article explaining tempo prescriptions. You might find it interesting to read.
What Speed of Movement Should I Use?