In the scene right after the Warden runs into the wall, Evelyn, Rick, and Jonathan are sitting on logs around a fire. Jonathan is looking in the Wardens bag and all of a sudden he yells out in pain. Evelyn says "what?!" and he told her it was a broken bottle. When he pulls the bottle out of the bag, it isn't broken! Go figure!
The neck at the top has been broken off, and there is a cork shoved into the top. Maybe there were some bits sticking out the side of the top, and the cork was shoved so far in that bits of glass still stuck out. Ha.