That would be very rare to see a FA open a door. AC has a very firm policy for only gate agents to open doors. I have never seen a FA open a door and have waited as much as 15 min for one to show up.
I can only recall one case, and a GA was present, but it seemed like something was sticking on the outside, so the FA tried from the inside, and it worked. That's of my 600+ flights on AC/rouge/Express. So I agree it's very rare.