>CC has market moving potential so can't be held during market hours<
There is no rule against holding an important CC while the market is open—lots of companies do it.
Poor word choice- it wouldn't be advisable but is legal as you say.
>Note both recent PR's on this subject (Sept 11 and Oct 9th) were both released before the market opened<
This is a separate issue from what time of day the CC is held.
How do you figure? All the potentially market moving news from COR on the FDA hold has been released when the market is closed- seems obviously deliberate on COR's part
BTW, even the original hold was announced before the market was open