Mass Effect: Deception is riddled with canonical errors, fans have found, and they're not content with letting them go under the guise of "artistic liberty." Some have started a shared Google document to chronicle every error, and have so far added more than 80 infringements, arranged by "Lore," "Timeline," "Characters" and "Oddities," complete with clarifying descriptions.
Some of the most egregious errors include Nick and Gillian aging six years in the three years since Ascension, two volus wearing clothes that would cause their immediate deaths, and [spoiler] "Anderson thinking that the Citadel trap had been sprung 'so successfully' they were still reparing damage -- The entire point of the first game was that you prevented that particular Reaper plan from succeeding."
There are plenty more on the list, which is available for public editing. The author of Mass Effect: Deception, William C. Dietz, is a video-game-novel veteran, having written Halo, Hitman and Resistance novels. He is not, however, the writer of the previous three Mass Effect novels (Drew Karpyshyn), nor is he J.K. Rowling, thus forbidding him this handy excuse whenever canonical inconsistencies spring up: "It's magic."