The guy was a DB for even approaching you about the matter.
I can't believe it would bother anybody that much to hear an aggressive exhaust note for what, a split second.
I would have given him the "thumbs up", smiled and revved it harder...
Current rides: 2010 CTS-V sedan, black raven; 2010 Cadillac Escalade ESV, black raven
Gone but not forgotten: 2008 M5, metallic sapphire black, SMG; 2004 645ci, metallic sapphire black, SMG