Steve
Amazing how some people go right over the top. Unless the helo is flying extremely low there is no way they can look right into the windows of their house. Heck I was flying in the Police helo last week and even from 500ft you still need stab binos to get a clear look into somewhere on the ground so with the naked eye from even a couple of hundred feet doubt they would get much of an eyeful.
Maybe the helo is flying up the valley for safety reasons, who knows. Best way to work out whose machine it is is to get them to describe what it looks like, Jetranger type lines or like an egg (500 series) or smaller with boom (300C or R-22). Then get out your NZ Wings directory and see what operators are in the area and if they operate the type.
Guarantee it will only take a couple of calls. If you like let me know the details when you get them and will see what I can find out.
The one thing that gets to me is people like this complain now but if there is a bush fire or they need airlifting out then they scream for a helicopter to come and help them.
Regards
PR