Of course the situation was delicate, and required a great deal of negotiations and compromises; that's when democracy shines most, when all parts compromise to reach an agreement.

I'm just stating that no, the writers of the Constitution weren't "hand picked", rather selected by Congress among representatives elected democratically; and no, it wasn't ratified by francoist institutions, rather by a democratically-elected Congress (and later on by a referendum). That's just revisionism that gets spread to fuel Catalan nationalism.