I don't know any "current Nazi" so I can't say, but from history, it's pretty easy.
Brilliant or useful ideas/work can come from morally monstrous or politically toxic people you know. Many people have done things that are very morally wrong (up to murder and so-on) and provide great things to the world, not that it "compensate" in anything, but both can be true at the same time (do bad & good at the same time, or during different life periods).
You need to realize that millions at the time of Nazi regime were "Pro-Nazi", and many were scientists that invented great things, many were writers that wrote lasting pieces, many used their experience to actually to meaningful things later-on, such as avoiding that those terrible things re-occur, how do you explain this?
Let me give you another example: Programs meant for homeless, drug addicts, criminals... are often managed by former criminals, and they turned their lives around and decided to actually contribute to society instead of continuing to do harm (or sometimes do both at the same time).