There is a really good chance that bull will never die. I've seen dozens of archery kills in unit 15 where they pulled out muzzle loader bullets from years past. One bull had two 500 grain slugs in his hind quarter and one barnes expander MZ in his front shoulder. All shots appeared to be at least a year old. I shot a bull on the shoulder once before as well and it knocked him down. 1 minute later he got up and ran off never to be seen again. We ran out of blood 2 miles later and followed his tracks for another 5 miles before loosing the bull all together. We spotted this bull (7x8) the very next year and 2 years ago he reappeared as a 370 class bull. Same area every year.
Point is, those muzzies aren't that powerful if you don't place your shot well enough. I hope he turns up but I thought you might want some real world experiences from my end no matter how bleak they may be.
Good luck to ya.