Thanks Stefan, but when I set Errors, the Grid fires the Error event and does not display the data. I still want to display the data but also add a warning to the page.
I see here that the DataSourceResult can be sub-classed to add my own properties. This works, but isn't a great option because it requires a copy constructor to copy the public properties of the DataSourceResult to sub class. Luckily, it looks like those public properties are all that is required from the DataSourceResult, but a future Kendo MVC release could cause it to break.
Is this the only option? What if I make my own AJAX request to retrieve a response that includes a bunch of my own data and a DataSourceResult. Can I set that DataSourceResult on the Grid programmatically or is the Grid required to initiate the request?