In all societies a 41 yr old man should be busy working on his career and raising a family. Not traveling 7000km to meet some university student and staying for months not working. Most of this kind of "tourists" have a strange past eg. ex-prison, drugs, paedophiles, psychos, sex tourists, social misfits etc and that is why they cannot easily fit in their own society. The easiest way out for them is to run to some 3rd world banana republic where they will be worshiped by awed citizens, particularly by the women. Be wary of any tourist traveling alone, or one who promptly hops into a plane to come and see you.
In this sad Agumbi case, one can tell that the guy isn't normal, that he's a psycho, just by looking at his face. Poor girl, how could she tolerate such a monster. (NB: Even, in western countries any relationship with a couple having >7yrs age difference is treated with alot of suspicion).