That happened to me too. I actually WD from the tourney I was in when it took me 6 shots to get out. I think it's just an error in the lie. It's not 15/20, it's more like 80/90. If presented with a similar situation, I would take my 64 degree wedge, use the punch shot, and hit it about 3/4 and hope it stays on the green somehow.
It also seems to be unique to that hole. Mulch lies in other places at Kiawah play like they are supposed to. Since my "incident" I am extra careful to make sure I'm not that long at #7.
GL, sounds like you just got really unlucky.
Clarence