Is it possible to argue your case (as in the lessons) if DuoLingo deems your translation to be 'wrong'? I can't see the option (if it exists)
There are two things you can do, you can click the 'still think you're right correct?' or click Feedback, both of these can be used for the same thing and Duolingo team have responded back and taken my feedback into consideration.
I suggest you use Feedback as it is more flexible, just make sure your message is clear.
I use the "still think you're right" option all the time. I write down every sentence and though I usually spell something wrong but If I am exactly the way it was answered perviously I mention it. Also if they use word I have never heard before in a sentence spoken by that robotie thing. It's hard enough to understand without them throwing in curve balls.