No, I don't think anyone is even alledging that he did, just that he "may have".
From the other story linked it sounds like he was just trying to push his way through the crowd and thought it was a good idea to say "Secret Service coming through" to get people to move out of his way.
“the person who had a messenger bag slung over his shoulder.
The man was walking his bike toward the World Trade Center, saying “Secret Service, Secret Service coming through.”
Dumb azz bike messenger?