CathInfo.com

Same applies when a person ostensibly seeks baptism into the Catholic Church, but he dies before he receives the necessary baptism of water and Spirit. "Desire" alone doesn't constitute a baptism. God knows the hearts of all men, and if a person sincerely seeks baptism into the Church, God will send him a valid priest for baptism even if he lives in the most obscure location and difficult environment.

Yep!  Even if he was a poor, lonely jew drowning in the ocean.

Yes it is negative doubt. You may have positive doubt regarding the ‘botched’ consecration, but you want to extend this to the conditional consecration too. Following this line one could extend this “positive doubt” to any subsequent consecrations by Bishop Webster (or, indeed, antecedent ones).

It easily extends to the conditional.  Father Pfeiffer went on and on about how the first one was valid, which immediately makes his judgment on the issue questionable.  So if all we have to go on is his personal assertion that the second one was valid, he no longer has credibility.  We actually have no proof that the second one even took place as alleged.  Father Pfeiffer has lost credibility as a witness due to his behavior over the years, including his persistence that this Ambrose character was a valid bishop despite all the evidence to the contrary that was put to him.  He's shown that he simply wants to believe everything is valid because he wanted to become a bishop.  That is plenty concrete.  It's not in the realm of "what if [any given unknown] priest at the altar botched the words of consecration."  All it takes to render doubt positive is a rational credible POSITIVE reason (something you can point to) rather than a "what if?".  This is well beyond the realm of what if.

It easily extends to the conditional.  Father Pfeiffer went on and on about how the first one was valid, which immediately makes his judgment on the issue questionable.  So if all we have to go on is his personal assertion that the second one was valid, he no longer has credibility.  We actually have no proof that the second one even took place as alleged.  Father Pfeiffer has lost credibility as a witness due to his behavior over the years, including his persistence that this Ambrose character was a valid bishop despite all the evidence to the contrary that was put to him.  He's shown that he simply wants to believe everything is valid because he wanted to become a bishop.  That is plenty concrete.  It's not in the realm of "what if [any given unknown] priest at the altar botched the words of consecration."  All it takes to render doubt positive is a rational credible POSITIVE reason (something you can point to) rather than a "what if?".  This is well beyond the realm of what if.

When has anyone needed "proof" a consecration took place? The fact that the priesthood is intact through Thuc, and that Aquinas addresses the fumbling of the words Bishop Webster butchered,  the burden of proof remains on those who express doubt about the consecration who have nothing except their doubt about Pfeiffer's person, which as far as I can see, is insufficient to negate the orders. Canon law even favors Pfeiffer's mind as to whether or not there was necessity to consecrate another bishop.