GetRenderer function returning null

Hello All,

I've been observing some unexpected behavior in the return value of GetRenderer function on contact list view.

I have Contacts List View open and in developer console I have executed below statement to get the renderer reference of the list applet with List Mode as visualization.

SiebelApp.S_App.GetActiveView().GetAppletMap()["Contact List Applet"].GetPModel().GetRenderer()

Above statement returned me a return, but then again after changing the visualization to Tile or Map and then try executing above statement I see null is returned and then after no matter how many times I change the visualization I'm not getting any reference to the renderer instance.