I have a lot of examples for this error, me and my friends do the same mistakes.
My friends who corrected the Schedule A got their visa
My friends who have scared about reaching CIC has also got their visa lol ...
I reached them after 15 months from the application (after medical pass) for fixing my error, and im still waiting.
One advice: tell the truth, reach them ... if you will be rejected for this reason (99% impossible) you can continue your life without saying: Oh why i didnt tell the truth ... because a US/CA or any others canada refusals is not a reason for decline PR.