It sounds like the being Muslim part was secondary to the being left by his wife part.
I have read other articles that quote friends of the gunman’s daughter. They discuss how the father did not like her non-Muslim ways. He did not like her clothing, her friends or her non-Muslim boyfriend. He went through her phone to read her texts.
Whether his primary anger was directed at his wife for divorcing him or his daughter for dating a non-Muslim, his Christmas Day actions reek of Honor Killing to me.
Yep I think you are right
Generally people don’t blow their own brains out in honor killings.
1) don't text
2) if you must text, delete it
3) same rules apply to voice mail, email, IM and all other such forms