Game 1 was probably the best game to dissect and probably the only game to really draw anything fruitful from in respect to both teams. Even before the series it was generally a series where game 1 would determine the momentum. Yes Faker's Fizz was a threat all in itself being able to counter all of the lockout that KT had. But I don't think that the game was make or break off of just that. KT's lockout combo could have come at any point and once in, there wasn't a way out. Hence where defenses come in, which is exactly what started turning the tides when the burst and immobility failed to take out a target.
SKT played exactly to where they needed to: to the mid/late game as closely as possible. KT's win condition came from being ahead and having that pick off potential and objective control. Where they faltered was in fear of the opponent's mechanical prowess; as shown at the Baron disengage. Fizz also became a monkey wrench in his own right, realistically able to counter Syndra (and even alter the build) along with the amount of stun impact should a reflex game came to challenge. With enough time, the attempts for KT to form picks turned into scatters in which Huni and Faker could initiate and pick off targets with whatever allies were nearby them.
Conclusion, the part that gets to me the most is KT's hesitance which is exactly something that a better team will feed off of the moment they sense it within your synergy. And it's that very lapse of coordination that turned the rest of the series into a cascade of inevitable demise.