The issue might actually be that they didn't know. It's on the accuser to prove their part (which, it seems, they now have?). It's not all that easy to verify

The issue might actually be that they didn't know. It's on the accuser to prove their part (which, it seems, they now have?). It's not all that easy to verify supply chains. So, say two parties have exactly the same lyrics for a song, must one of them be copy of snother?