Combine the BBQ sauce, crushed tomatoes, and brown sugar together in the slow cooker.

Add the pieces of pork and coat with sauce. Season to taste. 

Cover and cook on low until pork is fork-tender, about 8 hours on low. Cooking time can be reduced to 6 hours by turning the slow cooker to high. 

Remove pork from slow cooker and transfer to a large bowl. Use two forks to shred the pork, discarding any excess fat. 

Reduce the sauce by half in a small saucepan over medium heat and then add shredded meat. Mix well. 

To assemble burgers, spoon about 60 mL (¼ cup) pulled pork onto each bun. Serve with coleslaw.