It's boilerplate doctrine, settled at the first Council of Nicaea, that the character of the priest doesn't affect the validity of his functions.
Are you suggesting that the validity of his sacraments is questionable because of the enormity of his public and notorious scandal?
If so, what about the "validity" of his appointment to pastor the Basilica of St. Mary Major? Where do you draw the line? Does the crime have to be public and notorious, or could it be like the one Judas Iscariot committed in his heart when he left the upper room to go and betray Our Lord? If a silent mortal sin is sufficient to nullify the sacraments of priests, then who would ever know if they are receiving a "valid" sacrament?
We could go on and on with that one. For example, the bishop moves a priest guilty of pederasty ("pedophilia" is a media-confected misnomer) to a new place where he can persist in his crimes, then the pope moves the bishop away thus enabling his deviance to continue, and meanwhile, the pope who enabled the bishop to perpetrate corruption dies and is popularly acclaimed "a saint." Which level of crime is greater, the first, the second, or the third? Are all three actions equally "invalid" by dint of the associated notorious scandal? Does the society that makes acclamations of sainthood under such clouds of title lose its "validity" as a society??
On the other hand, if your comment was intended to draw attention to the separation of the power of the minister from the guilt (and just consequence) due to his crime, that's a whole other topic. Is every deviant prelate (or priest) above public scrutiny when his superior scuttles him away and reappoints him as if to excuse his defection?
Is every such case at least worthy of our disinterest, such that we would continue in our manifest error?