Three of us went to climb in Ban-y-gor despite it raining gently. One of us decided to start with a short HVS which was at the top of his experience in the dry. He fell or slipped a few metres up. One of his pieces of gear ripped out, which may have been as the rock may have moved or the placement was poor, either way it meant that he hit the deck. After falling, he sounded as if he was choking but the ground was too uneven to get him in the recovery position so I propped him up against the rockface (I did not consider the spinal injury risk). At this point I realised the back of his head was bleeding despite wearing a helmet. I called the ambulance but did not realise they would need to stretcher him out due to spinal injury risk and I did not properly explain the access conditions thinking that they would be able to walk in and out. Hence they had to call back-up in order to hoist him out and we waited a long time in the cold. He was not completely with it. His helmet was cracked so had taken the brunt of the impact. He suffered a mild concussion and had stitches but otherwise was very lucky.