There was lots of prior art from the 80s for "write anywhere", which is a generally a consequence of copy-on-write on-disk formats. The write-anywhere thing is not really what's interesting, but, rather, not having to commit to some number of inodes at newfs time. Sun talking about NetApp makes sense given that they were the competition.
We don't know exactly what happened with Apple and Sun, but there were lots of indicia that Apple wanted indemnification and Sun was unwilling to go there. Why Apple really insisted on that, I don't know -- I think they should have been able to do the prior art search and know that NetApp probably wouldn't win their lawsuits, but hey, lawsuits are a somewhat random function and I guess Apple didn't want NetApp holding them by the short ones. DTrace they could remove, but removing ZFS once they were reliant on it would be much much harder.
We don't know exactly what happened with Apple and Sun, but there were lots of indicia that Apple wanted indemnification and Sun was unwilling to go there. Why Apple really insisted on that, I don't know -- I think they should have been able to do the prior art search and know that NetApp probably wouldn't win their lawsuits, but hey, lawsuits are a somewhat random function and I guess Apple didn't want NetApp holding them by the short ones. DTrace they could remove, but removing ZFS once they were reliant on it would be much much harder.