Another CTA Decision has come out, this time finding Air Canada at fault for "crew constraints". AC presented more evidence this time (compared to WS). Even though the FO was unable to complete their refresher training, and AC couldn't staff the flight due to the pandemic, the delta variant, new government measures, operational issues, third party staffing issues, and bottlenecked training, the CTA didn't find accept that as unavoidable despite prior planning (or lack thereof).