Pork Butt "rubbery"??

First pork butt that turn out "rubbery" and looking to see why. Think I have a good idea but wanted confirmation. Placed 10 lb but on BGE at 11pm and hooked up cyber q clipped to temp probe on dome at 215. Next day 12 pm and 13 hrs later temp only 153 via meat prob. Seem little low so moved meet prob near meat. Had reverse plate setter along with pan of apple juice grade and then meat. At this point turned up to 250 and foiled with little apple juice worrying would not be done in time. Dome temp near 300. At 3 pm meat temp 165 and climbing turned BGE up to 290 at grade and dome temp approx 320-345 at times. I had to pull meat at 5 which was now 187.
Meat was warm on inside buy very "rubbery". Not sure if correct term. I have never had this. The meat was not chared and figure that due to foiling. But rubbery meat wasn't sure about and didn't want to occur in future. I figured due to foiling also and cooking fast and high towards 60 percent of cook. Any advice??