In a large bowl, combine the vinegar, mustard, maple syrup, and oil. Add the apple and toss to coat thoroughly (to prevent browning). Add the cabbage and toss well. Season with salt and pepper. Let rest for 15 minutes.
Spread the barbecued pulled pork on the bottom half of a hamburger bun and garnish with the coleslaw. Top with the other half of the bun and serve immediately.