Well, most people use "valid Mass" as a shorthand for "a Mass that included a valid consecration". How do YOU define valid Mass?
All valid masses have valid consecrations, but not all valid consecrations are done inside a valid mass.
A valid mass MUST have a valid Offertory, Canon, Communion. The novus ordo has about only 30% of the Offertory and 40% of canon, (and who knows what little % of the communion) compared to the True Mass. Even the "leftover" prayers in the Offertory and Canon have been changed to delete any words which refer to a 'sacrifice' or 'offering'. The novus ordo changed the PURPOSE and theology of the mass from the sacrifice of Calvary to the sacrifice of Christ on Holy Thursday.
(Talk to any novus ordo person and they will say that Christ's sacrifice is His offering of Himself to us in Holy Communion ...NOT his sacrifice on the cross (this is total heresy from V2).
Or, they will say that the Mass is the re-enactment of Calvary but that the purpose of the mass is Holy Communion (i.e. Eucharistic Supper)...again, this is false). Very subtle changes in the theology of the novus ordo but very important.
Ergo, even if the consecration is valid, the Mass is probably invalid and immoral because the PURPOSE of the consecration is altered due to changes/deletions in the prayers. The prayers and rubrics in the True Mass form the proper intentions and purpose of the mass so it is always valid. The novus ordo has gutted so many prayers and changed those leftover that what remains does not supply the proper intention for the mass, using the prayers/rubrics themselves. That's why the novus ordo people do not have a true understanding of the sacrifice of the Mass, because the prayers/liturgy do not teach it clearly. So, as Cardinal Ottaviani said, the validity of the new mass "can be positively doubted" because the purpose/intention relies SOLELY on the PERSONAL intention of the priest and not the rite itself.
So the new mass has a double doubt - 1) is the priest valid? 2) is the priest's intention valid?
Who knows...