Because in my "onComplete" function, I'm setting the new state and some other stuff. If I comment out everything in the "onComplete" function, the animations finishes as it should, with no lag. Which, from what I can gather, means that "onComplete" is called before the animation finishes.
Nothing else, besides the animation is happening, so I'm not sure why any updates should be issued?
I'm using setTimeout and _.delay on "onComplete", because "onComplete" fires before the animation has finished everywhere. So if I set a 10ms delay, then the animation has time to finish before whatever is in the "onComplete" function executes.