The clue says "...is set aside", so it seems to me that the answer should match the tense of the clue, and I think that the answer should really be "overridden". As in: ...very small mistake is set aside..." should be "...very small mistake is overridden." To justify the answer "overrode", the clue should read "...very small mistake has been set aside", and for "override" the clue should read "...very small mistake that I set aside." OK, so I'm pedantic, but I still think that the clue is wrong.