Spray the inside of a crock pot with pan spray. Season pork roast with salt & pepper & place inside the crock pot.
Pour can of root beer over the roast. Cook on low for 6-8 hours, or until shreddable.
Shred meat. Save 1 cup of the root beer liquid from the crock pot, & discard the rest. Return the meat & 1 cup root beer liquid to the crock pot. Add bottle of BBQ sauce. Mix thoroughly. Heat mixture for another 30 minutes. Keep warm. Serve on a hamburger bun.