If the lifter was damaged to the point of coming apart and the cam was damaged there is more going on, IMO. You indicated that the oil pump was damaged and that likely was caused by metal debris in the oil. Which possibly is what caused the lifter to be damaged. Now you need to make certain that the lifter bores aren't scored and that the cam bearings are not scored. That metal may have gone most anywhere, into the oil bypass on the cam plate, up to the rockers, certainly in the oil pan. Really should check and clean it all, do a leak down and compression test to see if the cylinders are affected as that could be the source of the debris. Runout could be an issue too causing the problem.