Human teachers make mistakes too. If you aren't consuming information with a skeptical eye you're not learning as effectively as you could be no matter what the source is.
The trick to learning with LLMs is to treat them as one of multiple sources of information, and work with those sources to build your own robust mental of how things work.
If you exclusively rely on official documentation you'll miss out on things that the documentation doesn't cover.
If I have to treat LLMs as a fallible source of information, why wouldn't I just go right to the source though? Having an extra step in between me and the actual truth seems pointless
WinAPI docs are pretty accurate and up to date