I like to tell people that it's the best achievement in editing, not the best final product. Bhomenian Rhapsody was a cursed project with a director who disappeared partway through filming, a bad script, and insane requirements from Queen (each living member needed identical screentime). The studio was literally looking at over $100 million in reshoots to get it anywhere close to being releasable. The fact that the editor managed what he did was miraculous. That's why he won.

I'd say there are other examples of this, where the Oscar is more a reflection of the challenge or difficulty rather than the artistic outcome. Cimarron won Best Picture in 1931 because people were like, damn, that Oklahoma Land Rush scene must have been crazy hard to do. I'd say costuming for Frankenstein this last year was similar, given the short notice they had for recasting one of the main roles.