yeah, because they think the cardinals at nicaea gathered the motht auforitative version and that's bullshit, patent bullshit

nowhere in any of the books of the bible is the BIBLE referred to itself, so anything in the bible cannot be said to sanctify the collection as it is, at all, period

and of course there's probably parts of the various scattered versions (i have a book with 3 versions of enoch) that are bullshit as well

but genesis as in the catholic bible, and enoch both concur on the point about fallen angels defying the Lord and laying with human women and producing nephilim offspring, it's not even in question even if you believe the story that the catholic bible compilation is authoritative, it still even says that in it!

i'm not really sure what part you are referring to as being questionable though... there's three major parts that i'm familiar with, one relates to the prophecy and stuff like what later parts of Revelation refer to, one seems to be a prophecy itself, if the antiquity is true, that corresponds to animal versions of several of the stories in Genesis (and we know that if it was from enoch then it's a prophecy, if that part is faithful to the history) and then there is a third section that for me reads a lot like much of the text of Plato's Timaeus (and similar to Corpus Hermeticum and the first section of Vishnu Purana) 

 several places in the catholic bible even refer to how large parts of the Word of God would be hidden from the world for a long time and revealed in the latter days

it's hard to take many of these scholars seriously when they are indoctrinated with the catholic canon, when obviously even the extant modern Orthodox and Ethiopian Orthodox churches have a different canon