I have always considered that when non cannonical books are quoted IN scripture they contain a truth God wants us to have ..they are inspired PORTIONS of generally not inspired books..(Does that make sense?)
It makes sense, but I dont think we need to stretch inspiration to include extra-canonical books.
I think it's sufficient to say that truth is truth, and when something extracanonical says something true, Scripture is free to make use of it.
But the doctrines of infallibility, etc., do not apply to non-canonical writings. Use them at your peril.