Just to add more color - 

Sometimes malformed HTML like missing close tags or an unbalanced quote can throw off Telerik even throught the application might continue to work fine manually.  The symptom is usually Telerik clicking on the wrong element - the locator says one thing, but the action is taken on a different element.

For a novice user, the symptoms look like a Telerik bug - for the experience user, finding this malformed HTML can be very difficult.

The request is for Telerik to be able to help diagnose these issues - they are in fact client application issues.  If Telerik could make it easy to track these down, it would flip the situation from something very frustrating to a positive outcome for Telerik "we helped you find the malformed HTML in your application".