I have something similar in one of my codes. Basically, as I loop through my query results, I generate p elements and then append these to a div in my side panel. Would you be able to append the tc.domNode generated by your function getWindowContent to a div rather than setting it as the content for the infoTemplate? I haven't used tabbed infoWindows before so I'm not sure if the same would work for you, but it worked pretty nicely for me.