Yep, on a lot of the later stuff it won't let you carry on with an update if battery is too low.

Regarding putting an earlier cal on, as I posted above it used to be possible, but it maybe that newer revisions of the IDS (Ford diagnostic tool) don't support that function anymore. When the IDS was updated by CD you used to get a seperate disc full of the updated calibrations, now it's all web-based.

The only other way of doing it is to completely put the car back to factory settings by AS BUILT data. Again, I would hope the dealer involved would know this or be guided by Ford technical.