I don't know why your husband wanted a cop there. A good reason would be that the cop would be a good witness to testify on his behalf if you were to allege something that was not true such as family violence or if you were to hit him and later allege that he hit you. Perhaps the fact that he is so much larger than you made him concerned. If he brought a cop, at least he planned on behaving himself.
I don't think you have a claim for invasion of privacy.