Derek Parfit's Persons and Reasons deals with this question a little more formally, resolving the tension with the concept of "rational irrationality"[0, p12]

I think what Nielsen is getting at here is the idea that a commitment to accuracy doesn't necessarily entail an unwillingness to be wrong. As in Weber's case, the wrongness of one's work doesn't necessarily imply it's unimportance.

[0] http://www.chadpearce.com/Home/BOOKS/161777473-Derek-Parfit-...