Reports on the highly respected Alan Arnette website quote David Roeske "Yesterday just as @fredrikstrang and I were about to leave after a night at camp 3 (7,000 m), we heard a radio call that a missing climber needed rescue high on the mountain. He had fallen off an ice cliff, and been solo on the mountain for 36 hours without a stove to melt water. The climber had been presumed dead until a drone pilot from K2 basecamp spotted him still moving and off route. We headed first down then up the mountain with rope, water, and medicine looking for him and were later joined by Tenji Sherpa from Summit Climb. With the help of the drone pilot we were able to eventually locate him in very dangerous terrain — a fall would’ve taken him either down a crevasse or all the way to the base of the mountain — and the three of us got him down and into a tent at camp 3 just as it was getting dark. Then the Summit Climb team took over."

Rick Allen and Sandy Allen

Early reports from Summit Climb, lead by Dan Mazur, made a cryptic post on their site that “Rick Allen disappeared at 8000m/26,000ft on his way down from the summit of broad peak, the world’s 13th highest mountain. He was reported dead by his team mates who took his sat phone and descended.”

In a follow-up on Sandy Allen's blog  more details of the rescue states that "Sandy and Rick are now both back at Base Camp following a couple of days making a summit attempt. Sandy returned back to camp himself after deciding to descend due to high winds. The rest of the team stayed at Camp 3 and considered their options for the summit. Rick made a summit attempt on 9th July after climbing all day and night. Rick was missing from the group and feared injured from 9th July until he was spotted by a drone, piloted by climbers at K2 Base Camp on July 10th.

Broad Peak in Pakistan's Karakorum Mountains

Sandy, with help from Andrzej Bargiel, his brother Bartek and their drone, was able to coordinate climbers that were already on the mountain to reach Rick at around 7.30pm. The climbers brought Rick back to camp 3 in the darkness. Rick returned to Base Camp today (12th June) safely thanks to Dan Mazur and his sherpas. After being examined by a doctor at basecamp, Rick is okay all things considered and has a few superficial cuts and some frostnip".

In an update (July 16th)  from drone operator Bartek Bargiel it would appear that Rick Allen slipped "on a frozen rock jump and slid downhill disappearing". He was missing, presumed dead, for 36 hours before members of a Japanese team spotted a rucksack, off route, at 7400m. At this point the Bargiel brothers, there to record a documentary of Andrzej Bargiels attempt to ski down K2, launched the drone to take a closer look at the reported rucksack and saw movement. Directing a team already on the mountain the drone operators were able to lead the rescue party to Allen's position, which has been reported as being "difficult access". Allen was found  and "apart from some freezes and bruises, he was reasonably well."  Reports say Allen was then brought down to Base Camp and has been evacuated to hospital where he is recovering. The drone operator was flying the drone to 8400m giving a unique position of viewing the mountain (8051m) from above.

In an interview with wspinanie.pl, in Polish,  the drone operator Bartek Bargiela reveals that a large serac broke from the 2km long wall and Rick slid 300m from the main route to Camp 3. He was first spotted using a telescope and on seeing movement Bargiela launched his drone, a DJI Mavic Pro that he'd reprogrammed for the documentary on his brother's attempt to ski down K2. Flying close to Rick Allen Bargiel was able to determine the coordinates and altitude. At this point Rick reports that he "felt that someone knew his situation", as a result of which he started to move upwards. Seeing that he was moving too high Bargiel then used the drone, flying it between Allen and the team who'd set out from C3 to find him, to direct the climber towards the rescuers Fredrik Strang, David Roeske and Tenji Sherpa. After a while Allen reached the rescue team and they were able to descend.