I don't use anything but rub, never needed any 'glue' for my cooks. I don't think the oil should have resulted in tough rib texture. I don't spritz, I do use a concoction in the last 30 minutes of any rib cook, that I believe adds flavor to the meat. I have abandoned temperatures below 275°F for ribs, but, there is no reason not to cook there.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"perhaps...but then again...maybe not..."