The Muslin Cleric for the Mosque actually defended the man when other worshipers were laying into him, preferring justice to retribution. Kind of amazing really, such restraint and compassion for the enemy.
It's because people of good conscience and good will, regardless of creed, colour, nationality, etc, are always capable of being reminded that, "We're better than this!" And most of us, when we are reminded of this, will try hard to live up to our ideals. We
want to be our best selves.
Also, restraint and compassion are pretty much things I've come to expect from most religious leaders. The vicious megalomaniacs (ie, the enemy, as you put it) may be loud but they are few in number.
It's still early days, with regards to the news, but it's beginning to sound as if the crowd outside the mosque had gathered to help a man who had collapsed on the sidewalk. It's still not known why he'd collapsed (low blood sugar due to fasting? a heart attack?), but he is the sole casualty reported.
It may be that the people hit by the van were only where they were because they were trying to help a stranger.