At this point I'm not going to do much about this, because a) Voltrex is in flux right now (see EdTheKet's plot quest) and b) I'm almost positive that the Voltrex yew tree is significantly easier to get than the other location where Yew can be found.
Also, Voltrex has not been balanced significantly since it was created, so "fixing" yew has other implications.
EDIT: Actually, thinking more about this, it's probably a lag issue, as all CNR should respawn with the same process. There's another possibility too, but it's really not worth mentioning. Server reset will fix both cases.