The 32-year-old model, who took part in a segment of the show that celebrated British fashion, told The Daily Telegraph that the supermodels and music stars present enjoyed tea and cake as they watched proceedings.
"It was actually surprisingly demure: all we were imbibing were cups of tea and coffee and having cake rather than anyone doing anything untoward," he explained.
"Everybody was behaving in a way that was very British. There were some of the biggest stars in the world in that room, but they all seemed to be conscious of the fact that the real heroes were the athletes and it just wasn't the time or the place for any diva behaviour."
Essex-born Gandy joined fellow models including Kate Moss, Naomi Campbell and Lily Cole on stage at the Olympic stadium. They showed off gold creations by Britain's foremost designers, including Christopher Kane and Vivienne Westwood.
"Everyone stayed for the finale," he added. "We were all in the holding room together, just glued to the spectacle on TV screens, like everyone else in the country."
Watch a video of the London 2012 Olympic flame being extinguished below: