It was a wonderful birthday message to John on his 33rd birthday where Gina hinted that Carlson's ear was reattached, leading us to the conclusion that Carlson's ear was at least partially torn off when he took the shot to the head before the Christmas break.
It certainly explains why there was so much blood after Carlson was hit with the shot, and also explains why his recovery time is still months. The Capitals noted that they expect Carlson back before the end of the regular season, so he should be good to go in time for the playoffs.