I have an apa in a keg right now and it's a little over half way gone. It was clear and perfect.
Last weekend I took it to a friends house for a get together. I brought it back home, and Now it's cloudy. The first 1-2 secods of pull is clear, but then it's really cloudy.
I am no expert, but it seems like moving it around stirred up yeast that had settled to the bottom. Probably tries starts settling back out, but if you keep drinking probably doesn't have the chance to.