Ref. that Swiss TV picture(screenshot)
It appears unrelated to the crashed flight!! The Text attached to that TV picture only says: One of the last pictures of the flight. Neither does it state wether that JU52? is actually HB-HOT, nor does it state the date when the picture was taken. Good guess it is just the normal journo crap - Mr. T would call it "fake news"
Canton Glarus is north of the crash site. Enter "Chamm, Glarus" on Google Earth (Maps) and it will show a mountainous place to the north of the accident site. Itīs nowhere said or written that they crossed that ridge next to "Martinsloch" and returned crossing that ridge again !!