I agree with you, sheckwes — mostly. However, this could lead to excessive cancelling and letting learners overlook too many errors, which would mean creating habits of bad practice and formatting. I suggest better parameters for Oh Noes to even show up. He needs to update to the latest syntax and versions of the programming languages used on Khan. That would lead to much less unnecessary appearances of our annoying, useful error buddy.

Just my thoughts.

You can always write your code between comments ( /*  */) and remove the comments when you want to check the code.