Did some more research, and I think the bolts with the o-rings are a newer BMW design that superseded the bolts that use a crush washer. Ron Stygar's tutorial shows the same bolts that came off my car.
Even though
realOEM shows the bolts using an o-ring also have a crush washer, I don't think that would make sense. Newer BMWs whose differentials/final drive plugs have an o-ring bolt don't use washers. Also, the torque spec for o-ring bolts is less than ones that use washers (44 vs 52 ft-lb).
Anyway, I'm just going to use the old bolts with new washers. The only reason I got new bolts is because I thought the old ones would have o-rings and needed replacing.
Thanks for listening! Maybe this will help others who come across the same dilemma
