One of fashion’s enduring fascinations is the way it’s bedeviled by unwitting synchronicities. John Galliano’s last-season couture show for Maison Margiela — Artisanal, as it’s more popularly known — featured an archly contrived orgy of cinematic gun violence that sparked the ire of our American friends. “Cinema Inferno” was its title, and, on Sunday night, there was a graphic reminder of its impact in the basement of Maison…