Going back and looking at the photos, it appears the spun rod bearing failure started with the main bearing failing first. Oil starved or clogged oil passage or some unknown reason stopped adequate flow of oil to the main bearing which supplies oil to the rod bearing. The main bearing starving the rod bearing of oil, caused the rod bearing to overheat, excess wear and then to spin within the rod. Tangs, as you seem to think would prevent bearings from spinning, would not have prevented the bearing in the rod from spinning if this case.
2015 F350 Ultra Lariat 6.7L CCLB DRW 3.73 Limited Slip, Green Gem Metallic w/ Caribou accent, Camper Package, Titan 65gal tank, Rapid Heat, Block Heater, Upfitter Switches, Dual Alternators, Camper Package, Cable Lock, Husky Floor Liners, Spray in Bedliner, 5th Wheel Prep, 25K 5th Wheel Hitch, Ford Goose Neck Hitch.
Traded 2011 F350 XLT CCLB SRW 6.2L gasser 6,000 miles for 2015
Sold 1996 F350 XLT CCLB DRW 7.3L 208,000 miles