Not sure on your particular problem, since you said you were in fact on stock slot. But a few comments just in case it helps. I had problems with every single rom that I did NOT put on a freshly wiped stock slot. Any other slot always created problems. I also ran into many various issues when reinstalling my titanium backups. So the last install of Alliance that I made (the current rom that I'm using now, for the last couple of months), I kept it to a very minimum. I used titanium to reload my texts and maybe a few game apps (data only), that was all. I always use google to restore my contacts, emails, etc. And my pictures, ringtones, etc are always stored on my sd card. I know allot of people rely heavily on backups, but I usually have more problems than what its worth. Hell, up until the last couple of roms, I never even made backups. If I bricked a phone, I just wiped and started all over. And the same every time I switched roms. The only thing I lost was old texts and my progress on solitaire scores, lol.
As far as your specific problem. The only thing I would suggest is try thinking of any sort of settings or apps that might link the flashlight or torch feature with the camera. I don't use any other apps, but I know there are allot of alternative torch apps, and also ones that use the camera, like instagram, etc. The only experience I have with any related error is if I try to open the camera while the torch is on, it force closes the camera. Turn off the torch, reopen the camera, all is back to normal. I'm using the stock camera, and stock torch app...