No drops or impacts to speak of.
Probably a swelling battery pushing something into the lcd.
The screen actually would not illuminate for about a day, but in very dark conditions there was the faintest red characters or numbers in the lower left side of the screen.
Took the watch into Apple on September 21, and just got it back free of charge(I do have AC+) today, October 3.
No explanation from the Genius. The pick came in a white kind of retail looking box versus the normal refurb style boxes. Maybe a sign of watches being offered without bands?
My receipt lists the price of the replacement as $329.