OK, I will be that guy. I sauce my Ribs when hell freezes over, so fairly cold LOL.
But to give this post some redeeming quality. I recently did some experimenting with Pork Steaks, trying to finish them off short of like burnt ends, and found exactly what you found, once sauced between the time it takes you to sauce, the cooling of the sauce itself (unless its boiling its probably cooler than the meat), and the evaporation effect, you IT is not going to recover for a long time.
I haven't done it yet, but for my next attempt at porksteaks ala burnt ends, I plan to pretty much take them to their final IT before the sauce stage. Yes they will continue to "cook and render" but I don't think I have to worry about overcooking as the sauce seems to "set" the cooking and I am trying to go for that right before fall of the bone tenderness anyway.
So all that rambling and I am with AL, although I don't sauce ribs, anything I do sauce, like the chicken breast I did the other night, I sauce and more to the grill to set the sauce and get some crispy caramelized spots.