Not sure who's to blame, but the biggest problem at the Tahs is ball retention, and that is down to three things, penalties (and lots of them), poor kicking and poor handling. As I commented on the match thread, Whittaker stated at half time on Saturday night that holding on to the football was the biggest issue spoken about at half time, and the players clearly took absolutely no notice. I don't know what the coaching staff can do beyond run on and play the game themselves.
For me, one of the first things I'd be looking at would be on-field leadership, and not just the captain but two or three senior players. Team selection also comes into it, particularly if one or two players are continually giving away lazy penalties or giving the ball away through poor handling. Regardless of what else a player is doing, a side simply can't afford a player who continually turns the football over to the other steam.
Kicking also needs to be fixed, Edmed has been poor in this area, time to look at Bowen or Harrison.