> the clear argument is that, because drawing a line is hard, we shouldn't call for any action against those who have stepped over it.

I think you're putting words in his mouth. He doesn't want to see no consequences whatsoever for those who were involved with Epstein, GP argues that people are drawing arbitrary boundaries with no clear repeatable definition and then taking action on them. He wants to understand what precisely being "tainted" entails and why a particular definition is deserving of the consequences such a label entails. In other words, he rejects arbitrary and subjective persecution for an objective approach to justice.