A local Spanish climber who was not part of our group was on route and approximately at the height of the third bolt. There was a clear view of all of the route from the belay. Also the belayer was wearing a bicycle helmet and the rope and gri gri they were using didn't appear worn. This would suggest that they were new to sport climbing.
Whilst they were on route a member of our group came over and commented on the belayer's use of their gri gri. It appeared they were only using one hand, pulling slack through and then letting it hang, not keeping a hand on the brake rope.
Almost immediately after this comment was made, the climber fell. Their belayer panicked and grabbed the live rope which ran through and burned their hand. The climber tumbled and span down the wall until the belayer grabbed the brake rope and stopped them around 2m from the floor.
After the climber gathered themself, they got back on the route and climbed to their furthest quickdraw. From here they downclimbed whilst unclipping, shaking all the while and nearly falling off again. The belayer continued to use the gri gri one-handed as one of them was now injured. Shortly after they both left having not done any more climbing.
Belaying must be properly learned and properly carried out.
There should be good communication between partners, on and off the ground.
You should be willing to question someone's technique, even when there is a language barrier.
We could have offered use of our clip-stick to help them retrieve their quickdraws.
One of us could have picked up their slack rope and then questioned their technique.
Sport rock climbing
Minor injury, Burned hand
Slip, trip or fall, Belaying failure or error
Rescue Services Involved?