ColorSageWith snapchat, we don't know what would be a good solution. If we should refuses it to flip up the first time, then someone will complain about that and a delay is also not a good solution. The best solution for you is to remember to exit the app when the camera has been flipped back. The app will remember this.
I have this problem on Snapchat and face unlock and I didn't notice it in previous builds. When I'll have something to record with then can provide some recording.
Edit1: Reboot fixed face unlock rotation while issue on Snapchat requesting front-facing camera persists.