Originally Posted by Ron_L
Did you take any pics? Sometimes you can tell by the grain of the meat if it was undercooked or not. Honestly, it sounds like it was since you said that it was moist, but tough. Overcooked would have been dry and crumbly. With higher temp cooks the finish temp is typically higher in order to get the fat rendered and the meat tender.
I did take some pics and will post them soon. How would you recommend I heat the flats? They're in plastic wrap and foil in the fridge.