Did you use sacred sites to achive this?(Piety path)
Other civs were probably very low cultured too...i don't know how a player can win at that turn against me if i'm close enough.
You need a lot of cities to achive this, so you expose yourself against multiple wars, especially in nq games where they tend to ally to the strongest one(which i approve at 100%).
I once got beat culturally but the guy won on the turn 160ish with modern era and stuff. But that's only because we played on a different continent and he stayed isolated forever while i got into wars for about 120 turns and couldn't tech fast enough to stop him(he also dealed with poor players that turned into AIs pretty rapidly).
With equal opponents, i don't see how you can win so fast. So here, in this gmr game, with EEE_boy and RStark wandering around, it's almost impossible to finish that fast.
Some guys beat the AI in less than 100 turns at standard speed so...everything is possible i guess, especially with an awesome spot to do it like having many NW faith wonders, the right civ, etc.
Odds are, in fact, so low that it's nearly impossible just to ''think'' about winning so fast before playing a game. But still, kudos to you CraigMak you are a great player and i'm still impressed by your finish time. Now, try this against me