For some reason nodes with neighbors usually refuse to remove. If you had checked the logs, it probably said node is no longer in failed list.
There is a chance a full repair would help clear out the neighbors tables. You might need to do a shutdown and unplug for 30 seconds again first, then after it boots back up do a full z-wave repair.
It will take a little bit to notice any changes, the updates to the z-wave details are not instant.
You can also use a USB stick as a secondary controller to force remove them:
-- How To: Remove Ghosts using hub tools or a UZB Stick
