It's fine and even good to assume good faith, extend your understanding, and listen to the reasons someone has done harm - in a context where the problem was already redressed and the wrongdoer is labelled.
This is not that. This is someone publishing a false paper, deceiving multiple rounds of reviewers, manipulating evidence, knowingly and for personal gain. And they still haven't faced any consequences for it.
I don't really know how to bridge the moral gap with this sort of viewpoint, honestly. It's like you're telling me to sympathise with the arsonist whilst he's still running around with gasoline