Make the sauce. Add the tomatoes, green chilis, smoked paprika, chili powder, garlic powder, lime juice, and agave to a blender. Blend until mostly smooth but still a little chunky. Set aside.
Sear the pork. Season the pork with salt and pepper. Heat the olive oil over medium-high heat in a large heavy-bottomed pan. Sear the pork on all sides until nicely browned.
Load the crock pot. Place the pork in the crock pot and pour the sauce over it. Turn the pork a couple of times to coat it in the sauce.
Cook. Cook on low for 8 hours.
Shred. Use 2 forks to shred the pork in the slow cooker.
Make burritos. Use a slotted spoon to scoop the shredded pork into a tortilla, allowing as much cooking liquid as possible to drip away before the meat makes contact with the tortilla. Wrap the tortilla around the filling.