I see you didn't trim the fat cap off the pork butt. If you leave the fat cap on you will get the fatty slimy stuff around the meat. There is plenty of fat inside the big hunk of meat that you won't need most of the fat cap on it to keep it moist like you would say a brisket flat.
When pulling the pork you will still notice some unrendered fat inside of it still. I just make sure when I am pulling it, i remove the globs of fat from the meat.
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