It is possible to retrieve IEnumerable collection from DataSourceResult, but there is no option to get IQueryable collection that has not been evaluated. I think it might be helpful to use filters from grid that can be used to generate a query.
Posted on:13 May 2015 14:19
Unfortunately this cannot be a universal solution due to the reasons explained in this forum thread: http://www.telerik.com/forums/feature-request-more-options-for-dealing-with-datasourceresults
That's why I have to dismiss this suggestion, Mateusz.