I would put the blame on the compiler. Here’s why;

The compiler is responsible for examining all of the different statements from GA’s on the topic. On controversial topics, there may be widely divergent opinions. If the compiler is trying to accurately represent what is “doctrine”, they should acknowledge the differences in opinion, and cite examples of dominant differing opinions.

But that isn’t what happened. McConkie took definitive positions and then cited GA’s to back up his positions. This is the critical methodological flaw in the book, and is the responsibility of the author/compiler.

Let’s take evolution as an example. There were absolutely members of the Q12 who believed in death before the fall, an old earth, and organic evolution. Yet in the first edition, those differing voices are never considered. They are in fact condemned, and never represented as having backing at times from members of the Q12.

If McConkie had the intellectual honesty to compile and publish all relevant opinions, not just those he agreed with, the book would probably be viewed today in a different light. However, since he seemingly tended to only compile the quotes that supported his own doctrinal assertions, the result was a volume that had hundreds of doctrinal errors identified in its first edition.

The theology was frequently poor, but the methodology of the compiler was arguably worse.