I think this was a bit too easy to decline. Ensuring we have the right hooking points on the datasource to react when a communication error occurs and a way to 1 - switch to offline and 2 - queue the request in offline mode.
There's no universally reliable, cross-browser way to determine whether the web app is in online or offline 'mode', due to the reasons stated here (http://docs.telerik.com/kendo-ui/framework/datasource/offline#detect-browser-internet-connection). If you know of a trusted, cross-browser method to check online/offline state for web apps, feel free to share it with us, and we can reconsider.