I have implemented the Azure - Offline Sync based on the documentation / Sample provided by Microsoft Sample in my Xamarin Forms Application.
In the sample / documentati
The exception carries with it a copy of the server version. In my implementation of IMobileServiceSyncHandler
I therefore just return error.Value
and this seems to work.
A more extensive example of this kind of logic can be found in this MSDN blog.
The same author has another example where he shows how you can resolve the conflict in favour of the server copy or the client copy, here.