Photo etiquette?

Selvarasa Srirangan's father, Batticaloa, April 17 2007.

I hope you like this picture. It's the father of one of our drivers, sitting in front of his house. I asked his permission and snapped the shot last night when I thought the light was perfect.

I like the shot but there's another reason I'm posting it: to challenge a rule of etiquette. His wife died the night before and the family had cremated her two hours previously. When he'd greeted me he burst into tears and Sri's was trembling throughout my visit. So was it wrong for me to ask permission to take the picture? I don't believe there should be any firm rule. Of course, if the person asked is not free for politeness or another reason to answer honestly then it's wrong. But people (all over the world) often like being photographed and Sri's father admired the result in my camera's display. I think it's condescending to assume that a portrait shot is unwelcome.