Season pork with re pepper flakes, 1 tsp. black pepper and 1/2 tsp. salt. Place in slow cooker and add apple cider vinegar. Cook, undisturbed, 8 hours, or until fork-tender.
Meanwhole, in a large bowl, whisk oil, vinegar, 1/4 tsp. salt and 1/4 tsp. pepper. Add cabbage and carrots. Toss to mix well. Cover and refrigerate at least 30 minutes.
Remove pork from slow cooker but keep the liquid. While hot, use two forks to shred the meat. Remove any fat found between the shreds.
Skim as much fat as possible from the liquid in the slow cooker. Add about 1 cup of the cooking liquid to the shredded pork.
Top buns with 1/2 cup pulled pork and 1/2 cup slaw.