Hei Steve
Hmmm. Yes you are right. According to the "Namentlichte Verlustmeldung" von Plato were killed 29.05.1940. He was then Oblt. and still beobachter.
The other crew you mentions went down at Bukkevatnet in Narvik area.
http://ktsorens.tihlde.org/flyvrak/bukkevatnet.html
This crew has also been mentioned as crew of the Grøvelsjø plane in some papers.
regards Kjell