Objectivity of the Sacraments and Intention: How Can They Coincide?

I was reading a bit on Apostolicae Curiae (I don't think that's the correct title because those are two 1st declension genatives in Latin), anyway, it's the 1896 one that declares Anglican Holy Orders "null and void". I was also thinking about my baptism which I've written a blog on before (It was done in the Baptist Church as a believer).

Donatism is described briefly by the great Wikipedia as:

"the Donatists were rigorists, holding that the church must be a church of saints, not sinners, and that sacraments, such as baptism, administered by traditores (Christians who surrendered the Scriptures to the authorities who outlawed possession of them) were invalid. Probably in 311, a new bishop of Carthage was consecrated by someone who had allegedly been a traditor; his opponents consecrated a short-lived rival, who was succeeded by Donatus, after whom the schism was named. In 313, a commission appointed by Pope Miltiades found against the Donatists, but they continued to exist, viewing themselves, and not what was known as the Catholic Church, as the true Church, the only one with valid sacraments."

They believed that the sacrament of Penance could not remove the contamination that these clerics had brought upon themselves and that their sacraments were invalid.

Now in response to this the Catholic party declared the sacraments worked:

"The Catholic position has always been ex opere operato — from the work having been worked; in other words, that the validity of the sacrament depends upon the holiness of God, the minister being a mere instrument of God's work, so that any priest or bishop, even one in a state of mortal sin, who speaks the formula of the sacrament with valid matter and the intent of causing the sacrament to occur acts validly."

The key word here is "intent". The declaration that Holy Orders had been improperly conferred with the Anglicans was because of their intent being faulty. But the question remains, how does this not fall under at least a semi-donatist interpretation.

For example, heresy, a mortal sin if held obstinately and knowingly against Church doctrine would effect the intent of a minister. But the statement says that mortal sin doesn't effect the procuring of the sacraments. So for an example:

Fr. X is a modernist who denies the sacraments have any "magical" power and just reads the formula but doesn't actually believe anything is happening. The validity of the sacrament would not be questioned if he had been a theologically orthodox murderer, but it is questioned because he is a heretic.

This seems to be the Roman position at least up until 1896. But this seems to be full of problems, because who can know the intentions of the heart except God? Theoretically any sacrament could be called into question. I've heard Priests say "we don't baptize babies because they're sinful" (which is heresy, St. Augustine clearly shows they are born with Original Sin), so does this mean all of the baptisms done in that parish are invalid?

The issue is even further complicated when you leave the Roman fold. For example, in my baptism at the Baptist church they made a speech before I went up saying "this is just an empty symbol of his profession of faith, it does not do anything spiritual" and then I was baptized with the trinitarian formula. So the formula was right, but obviously the intention was not.

But when I consulted our Monsignor (a man who has his masters in theology with emphasis in Canon Law), he showed me the document that stated that the Fellowship Baptists of Canada have been declared by the Canadian Council of Catholic bishops as valid.

Chesterton, Tolkien, and everyone before the last 30 years or so was given conditional baptism when they converted. So what has changed since the Donatists and 1970? Has the meaning of the word intent changed?

It's a very small but important point I'm trying to figure the answer out to. For if the church declares Protestant baptisms valid in Vatican II, why don't they declare Anglican ordinations valid as well? (obviously it's useless now as they're ordaining women)

Canon Law will be the death of me.