I was about to begin my climbing session at the local indoor climbing wall. it was late evening and there were only a handful of people around. On my way to the toilet, I noticed a belayer using a Petzl Gri Gri to belay a climber on a steep leading route. The climber was about half way up (about 5 quickdraws up).

The belayer was not holding the dead end of the rope and were completely disengaging the cam by placing their left hand over the top of the device to enable them to pull the rope out with their right hand. They were positioned close to the wall and were attached to a sand bag.

I initially dismissed it but on my way back from the toilet, they were still doing it. It was at this point I intervened because it was clear they weren't aware their actions were likely to lead to the climber taking a ground fall and potentially give them (the belayer) serious rope burns if they slipped off.

I explained to the belayer that what they were doing was unsafe and why. I provided some guidance on how to pay the rope out safely. Meanwhile, the climber was still struggling to pull enough rope up to clip so they decided at this point to be lowered off from the route. As they were doing this I noticed that the rope was very twisty which undoubtedly added to the belayer's difficulty to pay out.

I tailed the rope as they were lowered to the ground and explained to the belayer that they were not to blame for their inability to use the device safely and suggested they take further instruction.

I mentioned the above to the duty manager of the wall and they confirmed that the belayer was signed in by the climber as a novice and should not have been belaying without supervision.