Max Kellerman punched harder than Marcellus Wiley. Evander just punched the machine and didn't get it better than any average joe.
I saw a show where the punching power of Mia St. John was tested against a generic male junior welterweight. Her punching power measured higher because she put everything she had into the punch while the male welterweight threw a right cross with proper form. I guess I said all that to make the point that although someone might register a harder punch, it doesn't necessarily translate to punching in a fight.
[yt]BJxCiJYDYRg[/yt] Looks pretty accurate to me. Evander didnt put any weight or speed behind the punch, it was more of an arm punch. Also the machine measures the impact of the swinging ball, so its more a case of measuring how fast the ball is pushed rather than the initial impact of the punch. So the weight which you feel in a punch wont really factor too much into this machine, nor that snap feeling, a snappy punch may cause a lot of damage but doesn't cause as much transfer of momentum.