A good reminder when engaging with a source that speaks on much — some topics better known to you, some less:
If, when it speaks of topics you know well, it seems unreliable, but then, when speaking on topics you know nothing about (or are simply no expert), you accept it as an authority, you are doing yourself no service.
You need other sources.
Judge your sources first by what you know best. If they seem reliable in that regard, you can begin to cautiously trust them when they venture into waters more unknown to you.