My guess since you didn't rest them in a cooler before going into the refrigerator, is that the internal temperature didn't go up much beyond 180 so pulling will not work.
You are probably going to need to slice them.
But then, this is just a guess since I have never done it the way you did.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle