Why did my water freeze so fast?

Technically speaking, liquids must be cooled to below their freezing point in order to begin transforming from liquid to solid. The reason is that some amount of supercooling is required in order to have energy available to create the new surface area (in order to freeze, there must be a new surface created, the surfface between liquid and solid which did not exist before the solid formed). How much supercooling happens depends on many things but, for pure tin in a clean test tube, it can be more than 30 degrees C. If you measure temperature very precisely in these situations, you see temp go below the freezing point and, as soon as freezing starts, the temp goes immediately up to exactly the freezing point (heat to do this comes from the latent heat of solidification).

If your water was "pressurized" because of carbonation or "extra aerated" water, the pressure lowers the freezing point so it may have been supercooled just a little bit before you got it out of the freezer and then handling the bottle nucleated freezing.

You are a cold hearted son of a gun