Article by embittered stunt climber who worked on the movie
The article was written by Chic Scott in the 1975/1976 edition of Ascent. He was embittered about nearly everything with the making of the climbing scenes. He was angry about Hollywood commercializing mountain climbing. He lamented about the movie “showing the wrong techniques and attitudes“ which he believed would be mimicked by others who would be killed. He talked about the real death of one of the stunt climbers and how the production continued to use ropes oozing with blood from real life accidents during the filming. He was embittered by the fact that it took a stunt climber dying before the movie company bought insurance for them; insurance that turned out to be worthless when he was injured on the ground. He had special criticism for Clint Eastwood. He believed Eastwood lacked a conscience apparently for continuing the movie despite all these issues. Scott felt that in trying to do all his own climbing and taking amateurish risks, Eastwood did not respect the climbing profession. The article is an interesting read and has some behind the scenes photos that show how they did the climbing stunts (you might have to use the reader view on your device to defeat a paywall)
https://rockandice.com/snowball/eiger-sanction/