Despite what the article says, Jazz is no longer an Air Canada subsidiary, nor has it been since 2006. It has always been a regional feeder airline operating under contract mostly with Air Canada. When operating under Air Canada contract, flights are shown as "Air Canada Express, operated by Jazz". Jazz Aviation LP is a wholly owned subsidiary of Chorus Aviation. The regional airline is headquartered in Halifax, Nova Scotia.
So the pilots are employees of Jazz Aviation and maintenance is also its responsibility, not Air Canada's. The "flames" are probably sparks caused by the wheel rotating and starting to come off its bolts as it came free of the ground. So I have to wonder what type of walk-around the pilots did before takeoff and what mechanic either left off the lug nuts or didn't sufficiently tighten them.? I guess the investigation will tell. At least no one was hurt, but there must be some significant embarrassment going on right now.