You may feel strongly about the fact that he shouldn't do it, but it isn't really your job to appoint yourself judge, jury and executioner, and go around policing other cyclists and telling them what they've done wrong.
You'll be wagging a finger at people without pedal reflectors and having a go at anyone who takes a corner a bit wide next if we let that continue!
And you of all people shouldn't be telling others off for riding on the pavement seeing as you've openly admitted in the past that you brazenly defy the law and ride on the pavement yourself when it suits you, i.e. when you feel it isn't safe to ride on the road, despite it being against the law and you could have terrified a little old lady hobbling along to the corner shop as you steam past, you hypocrite!