Re: Surprise in my oil change...
The tang is there to assist in lubrication of the bottom end. The plastic gear is sort of an oil pump that spins and forces oil up to the rocker arms. You'd be surprised how effecient it is too. Try running the engine with the valve cover off and you'll see just how much oil it moves. The tang isn't as critical but under extreme conditions you could starve the crank and rod of needed lube. You say you have over 1000 miles on the motor but you don't know when the tang broke off. I'd replace it if I were you and that will give you a chance to inspect that rod cap for wear, just in case. When reassembling use blue lable LocTite and be sure to put the rod cap back on the way it came off. Look closely and you'll see alignment marks that should me matched up on the rod and cap.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"