It has to be real since the Bank of Canada never released $20 sheets to the public. Therefore, it cannot be a fake error cut.
Not true, according to this old post (January 2004) by Kinghaku:
Well I know for a fact if you visit the BoC museum in Ottawa during regular buisness hours you can get your hands on sheets of anything you want. I was there in December and a guy from the states bought a sheet of journey 5s. I asked the girl at the counter about it and she says they always keep a few sheets of every denomination in circulation in a vault somewhere in the BoC in case anybody wants to buy them. Of course there is a premium attached, I think the guy paid 250$ for his sheet of 5s, but if you are in Ottawa before the 17th of March and go to the museum chances are you might be able to get your hands on a sheet of bird C-Notes before they dissapear.
Since reading that, I have been extremely hesitant to accept any kind of cutting error on any modern Bank of Canada note as genuine.
As for the colour bar though, yes I agree that that would indicate that the error is very likely genuine, because I wouldn't expect the colour bar to be showing on any uncut sheets available to the public.