I wonder if it would be a good idea to make it possible to comment on translations that are marked 100% but don't seem quite right (maybe this feature already exists and I can't find it). For example, translating from Spanish to English, "elaboration" was accepted as 100% correct in a recipe when, in English, we would never use that word when we mean "preparation".
It appears that you can edit 100%'ers, but its unclear to me that those edits actually mean anything. It would be nice if Duolingo would clarify that point. I would also like some mechanism to flag 100% translations as still being poor. Maybe a thumbs up / thumbs down system like appears elsewhere on the site. If a 100%er gets a certain number of thumb's down, then it loses its special status and is reopened for additional translations.