I think so. You seem to be arguing that, at some point along the "sin spectrum," the minister's sinfulness can impair the validity of the sacrament. For there is no sacrament without a minister. The sacrament is brought about through the minister. That's the way Jesus chose to bring it about. I believe that was Dave's original point - though his post was actually in reference to other sacraments.
Where did you come up with this one?
The disciples weren’t ministers when Christ gave them the example, and when Paul told the church at Corinth they were doing it wrong, and carefully explained how it should be done, they weren’t ministers and he never alluded they had to be.
Scripture please
JH