MY NEIGHBOUR...A true story.

Who is your neighbour? 'A person living next door to or very near to the speaker or person referred to'. My friend gave me a 'gist' recently of how he got into a fight with his wife. Ehn, so this is not unusual. However, the trigger of the fight got me thinking.
His wife had travelled out of town for a few days.Upon her return, her neighbour (whois a pastor) hailed her and said, ' Welcome, i think say you and Oga na in travel o. Because Oga sef no dey for like three days. i never see this gate open make e enter for days now'. Ofcourse 'Oga' did not travel but apparently was away from home (without the knowledge of his wife) for a few days as well. Now wife, as expected is very disappointed and angry. A fight ensued and she accused her husband of infidelity, saying this is what he probably does whenever she was away.
The husband claimed that he passed the night at a friend's place around the office as the distance between where he lives and where he works is quite a journey. Anyway, i found this kind of funny and interesting and a bit confusing at the same time...the neighbour's involvement that is. Was the neighbour being sincerely concerned (being observant of who goes in and out of houses in his neighbourhood)? Was he being nosy? Or he just was being 'the christian' trying to prevent any room for infidelity? My neighbour's marriage is about 10 years.
As a man, how would you react to this situation? Ok, what if the circumstances were reversed (your neighbour 'hailing' you that your wife has been away also in your absence), would you react the same way sincerely? As a woman, would you encourage the neighbour? Especially since that may be your source of keeping tabs in your absence. As a neighbour, would you do the same, not necessarily out of being nosy?
I am just curious especially as this brings to mind another female friend of mine whose husband checks on (when he is away) by calling neighbours and asking if she is home. 
P.S: My friend is yet to resolve this issue with his wife. He wants her to speak to the younger friend of his whose place he (claimed) to have passed  the nights he was  away from home.