Update to the above, the alternator was not the issue. I initially tried it but only through 1 key cycle, but when I tried again through 2 key cycles the EML light remained light with the alternator disconnected. To date I have changed the cam position sensor, timing phaser & timing solenoid (all bank 2) on the advice of 'experts' but still have the same issue... I don't have a Bluetooth OBD II, looks like I'm going to need to either purchase on or put it in to garage for a proper diagnostic check.
Paul, I just had something similar and the alternator testing like you did, was inconclusive. However, after replacing the alternator I haven't had any problems in a couple of weeks now. Fingers crossed still.
Apparently, the alternator was just on it's start of going out and causing a slight whine on and off. When the whining came on, it confused the camshaft sensors. Ford actually had a bulletin about the issue too but I lost track of where I put that. I was about to replace the engine. Not interested in upgrading yet.
We did not have to open the engine up and replace the phasers or solenoid, although I was getting ready to do that with the roller-followers and upgrade the oil pump. But, since I just bought myself more time, I don't see a need to do any of the rest.