I remember that thread asking about starting before midnight, too, and what people wrote. I subsequently spoke to the Inyo N.F. staff person who gives me the unused permit numbers, and was told there is no restriction starting your hike before midnight. The permits are only necessary IN the Whitney Zone. The first leg of the trail is a no-permit-required zone.
Steve, I had the same conversation a few years ago with a semi-regular at the ESIVC and was told you can't leave the trailhead prior to 12:01 AM. I guess it depends who you speak to and when.
I've always found the rules and regs for Whitney area to be more complicated than they need to be.
