Are police officer actions with citizens 'private conversations'?

Interesting article in recent news, somewhat local to the Washington, DC area but really worth discussing on a national stage since it seems that the laws on the issue vary from state to state.

Traffic stop video on YouTube sparks debate on police use of Md. wiretap laws

The quick summary of the story, a guy on a motorcycle is stopped by the police for speeding and reckless riding.  He had a habit of wearing a helmet camera and recording his adventures so the camera caught the interaction with the police officer.  He cooperated with the officer at the time of the stop and then later posted the video of the event on YouTube.  Maryland, where the stop occured, has a law the precludes recording audio conversations - NOT VIDEO, only audio - unless both parties have agreed to the recording with the caveat being that the law only applies where there would be a reasonable expectation of privacy.

Apparently the police officers and/or prosecutors that are going after people that have made such recordings in the past, for example taking cell phone video of police making traffic stops and such, are arguing that their interactions with citizens that they are dealing with are all private conversations so they would, in effect, never be able to be recorded, at least not with any audio being captured.

Personally I think that's a load of bunk.  When an officer is on duty and/or acting in an official capacity they are serving the public and their actions should be public record -- unless they are operating in an undercover capacity.  If they are pulling over someone for a traffic stop, or if they're dealing with the public in a crowd control capacity (for example, the incident at University of Maryland a few months back) then they should have no expectation of privacy and there shouldn't be any problem with any individual capturing their image and voice.

As noted in the article that is linked at the headline, the officers themselves typically are being recorded by cameras and equipment that is on-board in their cruisers.  The public doesn't typically have ready or easy access to those recordings, but they are being made and the officers know that to be the case.  Also noted in the article is that officers have been repeatedly instructed to behave as if their actions are being recorded (so they act with restraint and don't do something that might result in bringing shame and dishonor on themselves or the departments they work for, or worse yet doing something that violates someone's civil rights and results in a very expensive judgement against themselves and the department they work for).  To me that is a sure sign that police officers shouldn't expect that their interactions with the public are private.

What say you?