Being wrong isn't corruption in and of itself. It may be stupidity, ignorance, or moronic, but its not corruption without bad motive. It's easy to attribute wrong motive, but it's much harder to prove. It is unethical to attribute a wrong motive when a more obvious and more neutral one exists. In this case, it's that they believed what they said.
Earnest belief does not free one from responsibility for what they write or say. But when it comes to adherents, those who chose to believe, the final responsibility rests on them. If something seems irrational, it probably is. Few schools teach formal logic today. But you can educate yourself to spot logic flaws. If one feels deceived by the Watchtower, the fault is ultimately theirs. We are responsible for what we believe. We cannot remove or deflect that responsibility by pointing to someone else, no matter how wrong headed their claims may be.
Another point to note is this: The phrase 'false doctrine' is common. It is also a bit of misdirection. Misleading, scripturally unfounded, illogical doctrines they may be. But they are truly doctrines. We should call them by a name that truly says what we mean. I'm not trying to create new phraseology, really. Intellectual abbreviations such as "false doctrine" can be useful shortcuts. But my personal preference is for a more exacting phraseology.
Being hurt by the Watchtower does not give one license to make things up. As Dr. Schulz and I write we encounter that repeatedly in the work of others some of whom have academic credentials. "Falsus in uno, falsus in omnibus" is a good working hypothesis when researching anything. If we or anyone on this board or another writer craft unfounded myth or suppose things without any evidence, we give grounds to reject both our work and us personally.