Racism...AT HOME!

Marina
So yesterday night something happened and let me baffled... I am posting it here so hopefully you guys can share your opinion on what should I do (and if I should do something). 
Me and my husband (he's of Pakistani origin) have moved six month ago into a new block of apartments. It's a gated community with communal parking, gardens, pool and tennis court. Last night we had two of his office colleagues (also Pakistani) over for dinner with their respective wives.
After dinner my husband and his colleagues decided to take a walk in the parking in front of the building. A lady ( a resident of one of the flats) arrived With his car and started to follow them around. After some time she approached them and asked my husband if he is from outside. He relied that he is a resident and she started to doubt it saying that she never saw him before. She enquired about the number of the apartment and his name. When he asked why she would want to know all these information she said " I find you guys very intimidating!". My husband is a respected professional and so are his colleagues and as I already wrote they were just walking around.
Today the building administrator saw us outside and told us that our apartment was mentioned in one email he received. There has been a complaint about three guys walking around the block and diving into the swimming pool at night. Thing that obviously didn't happen. 
Should we raise a complaint? If yes how? 
Thank you