Re: Bugged Corypheus Fight

Yep, had the exact same issue.

Can confirm that "defeating Coryphyspit too quickly" was the problem. 

Re-loaded the auto-save made at some point (can't remember if it was the start or the half-way point) during the battle and deliberately took it easy on the old guy. 

Got the cut-scene to trigger, and from there the end-game was a breeze.