Looks like you are right. I was confused because two paragraphs after the fall Willy is described as injured with no explanation how. And the phrase “apparently uninjured” seemed to foreshadow that whoever fell was injured after all.
[Wikipedia](https://en.wikipedia.org/wiki/Toni_Kurz) [explains](https://en.wikipedia.org/wiki/Willy_Angerer) what happened:
“During the ascent, [Willy] Angerer was injured by falling rocks loosened by the warmth of the rising sun as they crossed the first ice field.”
“A rock fall injured [Willy] Angerer in the head on 20 July 1936, forcing them to descend.”
Looks like you are right. I was confused because two paragraphs after the fall Willy is described as injured with no explanation how. And the phrase “apparently uninjured” seemed to foreshadow that whoever fell was injured after all.
[Wikipedia](https://en.wikipedia.org/wiki/Toni_Kurz) [explains](https://en.wikipedia.org/wiki/Willy_Angerer) what happened:
“During the ascent, [Willy] Angerer was injured by falling rocks loosened by the warmth of the rising sun as they crossed the first ice field.”
“A rock fall injured [Willy] Angerer in the head on 20 July 1936, forcing them to descend.”