Valentine Gallagher (April AD2000) quotes some authorities claiming ambiguities in the documents of Vatican II.
Surely the documents themselves clearly and unambiguously confirm the Church's teaching that the Holy Father is the sole arbiter in such matters: "For in virtue of his office, that is, as Vicar of Christ and pastor of the whole Church, the Roman Pontiff has full, supreme and universal power over the Church, and he can always exercise this power freely" (Lumen Gentium 22).
And: "In this Church of Christ the Roman Pontiff is the successor of Peter, to whom Christ entrusted the feeding of his sheep and lambs. Hence by Divine institution he enjoys supreme, full, immediate, and universal authority over the care of souls" (Christus Dominus 2).
There has been ample time since the publication of the Vatican II documents to obtain a definitive ruling on any ambiguities that may exist. I have discovered none in the Vatican II documents I have read, but I realise that dissenters can employ "creative interpretation" to cast the illusion of ambiguity.
I believe that no set of documents has ever been less carefully studied yet more widely quoted than those of Vatican II.
North Blackburn, Vic