[GAMEPLAY] Match Loss Despite Nexus Not Destroyed

So I was enjoying a game where we were more-or-less playing from behind. I secured every dragon of the game, and I secured baron, as well. My team wasn't exactly ideal in their knowledge of engaging and team-fighting, but we were able to hold for 40+ minutes since the enemy team didn't get a single dragon (and we got 5th dragon twice and a baron). So the game disconnected for everyone. Okay, client issues. Fine, I get it. I wanted to see the timer on the game clock; nothing too out of the ordinary. Upon further "research", I saw that the game never registered our Nexus Turrets being destroyed in the "Building Kills" tab. I checked other games to see if this was the case for other logs, and they do show the Nexus Turrets as destroyed in their games (when they weren't surrenders). So, technically, we never lost the game since our Nexus wasn't destroyed (since we never lost our Nexus Turrets). Why is this? I fought quite long and hard over this game, and it's going in the books as such without the Nexus Turrets being destroyed? Why is this the case? If they were never destroyed, then why did the game end? If the game was canceled due to server issues, then why isn't a "ghost" game that disappears from Match History? What determined this game as a Loss?