Bob Dylan hasn't killed anybody so I haven't a clue how I would feel about his music in that hypothetical event. I might be affected or I might not, I don't know.
Bob Dylan's art versus the Nanny Goat's? I don't know about you but as it stands now, nobel prize winner Bob is a messiah in the world of art/music
I might find it difficult to separate Bob from his art or I might not and carry on appreciating his work. but i have no difficulty with consigning Humphries' tiny contribution to the world of art to the dustbin.
Therefore your argument is fallacious.
Even if you use a more realistic example , say Michael Jackson .
If a person really liked MJ's music but believed him guilty of child sex abuse, did it affect that person's relationship to his music?
However, even with that more realistic example, Jackson's contribution to the world of music and art is by an infinite factor, much greater than Humphries'. so I might well make an exception and still hold MJ´s music in high esteem, just as I might Mozart's music.
I don't have that much of a relationship with Humphries' work, in the scheme of things it made a very small contribution to art and culture in society, it's in the past and I can just forget about it without missing a heartbeat.