The group of 3 had set out for an early evening walk and were nearly finished when they realised a set of keys was missing. Retracing their steps they made their way back up the mountain to search the ground, and in the process split up. Although well equipped and with good torches, two of the walkers lost the path and found themselves on broken and steep ground on the south ridge, at which point the alarm was raised.
As Team volunteers made their way to meet them, the party had managed to reunite and were making good progress down the Minffordd path when the two groups met up. Having established that the walkers were warm and well lit, everyone continued down off the mountain and had reached the carpark by 11;00 p.m.
The keys were with the car, so might well have been dropped right at the start and reunited with the car by a fellow walker.