I just flew YYZ-YYC this am and got my u/g on an oversold flt ok.But two PAX who had J class seats showed up late and were given middle seas in the rear.AC invoked the 20 minute rule and gave their seats away.It appears from the manifest that all J pax were either legit u/g or booked J as all were either E or P with one SE.My seatmate was booked J.