Last night’s post-screening discussion with (from left) ‘Freakonomics’ Producer Chad Troutwine, filmmakers Heidi Ewing, Rachel Grady and Alex Gibney, with moderator and financial advisor Alvin Hall. Photo courtesy Silverdocs. The 2010 Silverdocs festival got underway last night, with a slightly more sedate affair than the NBA star-studded red carpet function with the Wale-soundtracked afterparty that kicked things off in 2009. Last year’s party, though probably tame by NBA standards, was an approximation of pro…