CANNES, France — The 68th Cannes Film Festival was brought to a surprising close Sunday with Jacques Audiard’s Sri Lankan refugee film taking the festival’s coveted top honor, the Palme d’Or. While the dapper French filmmaker has drawn widespread acclaim for films such as “A Prophet” and “Rust and Bone,” some critics were disappointed by the climax of Audiard’s film. “This isn’t a jury of film critics,” Joel Coen said after the awards ceremony, alongside fellow jurors such as director Guillermo del Toro and actor Jake Gyllenhaal. Greek filmmaker Yorgos Lanthimos took the jury prize for his “The Lobster,” a deadpan dystopian comedy starring Colin Farrell and Rachel Weisz.