The B “winner” is actually in another event so not sure how his results got mixed up - he is in the ODZXentury Endurance ride on a different route.
Thats definitely a bug but to avoid this in future, use Zwiftpower results as it removed a couple Zpower riders from your event and you would have come first.
You didnt get a finish line likely due to a data/network error, which could explain why the “B winner” got sucked into your stats (your event routes crossed over in the desert) but I havent seen this happen before. You may want to log this with zwift support and send your log file to them.