Dear Guest
I don't know what the sex of the spouse has to do with it - when you marry, your possessions become joint possessions, regardless of whether you are male or female. The words in the church service are "all my worldly goods I thee endow", but whether or not the words are in the form of marriage the effect is the same.   In divorce settlements (which I've been involved in drafting in my previous day job) each party has to agree which items belong to which party.   In this case, he left "his" possessions and despite meeting up with her to discuss the divorce has done nothing to reclaim "his" guitar. No police force in the UK would touch this as an example of theft because it clearly isn't.
As for Guest Professor Lambeau - what century are you living in? Good grief! She didn't leave HIM in any case - he has left HER.