Why did my liquid soda freeze once I pulled it out of the fridge?

Your soda was in a supercooled state. Being in the freezer, it was at a temperature below its freezing point however it remained as a liquid as the glass was too smooth to allow ice crystals to start to form (in technical terms, the phase transition requires a nucleation site). When you removed it from the freezer, you gave it the disturbance necessary to catalyse the transition from supercooled liquid into a block of ice. No violation of the 2nd law occurred.