Supposed a battered wife is in hiding and a police officer knows where she is and the husband makes some frivolous lawsuit so he can see her - would it be so bad if the police officer claimed he didn't know where she was?

As for lying in Congress I would expect it if it was to protect the identity of a whistle blower or something like that.

The key in all parts are context, but Zero Justice explicitly denies context; it would be the same as giving the driver of a car what hits and kills a pedestrian because it gets bumped by another car the same punishment you would give for first degree murder.