Hatari UI (python/Gtk script) and Hatari (SDL program) are separate
processes with separate windows. Hatari window is just embedded inside the
Hatari UI window.
Which of these windows didn't go away, and which of the processes had
disappeared from the process list?
The 'hatari' process disappeared from the list. I didn't notice any other
hatari-named processes afterwards although perhaps there aren't any if its
python.
It just didn't look like a python UI to me - it looked as it does on
Windows with the SDL gui inside the Hatari window.