Killing the parent, tderandrtray, should allow the OS
to remove the
zombie, which is exactly what you are seeing.
https://unix.stackexchange.com/questions/74028/is-a-persistent-zombie-p
ro ce ss-sign-of-a-bug
That is pretty much what I suspected, that I had discovered a bug, but I
didn't really want to go through the steps of reporting it.
However ... in the interests of helping the TDE devs, and also for the
betterment of all humanity ... I will file a bug report, if somebody
points me in the right direction.