Can the police pull me over just for leaving a bar parking lot?

No. The police cannot pull you over simply for being at or leaving a drinking establishment. They need reasonable suspicion or probable cause that a traffic infraction or a crime is being or has been committed.

That distinction matters because of how these cases start. An officer parked outside a bar at closing has a hunch. A hunch isn't a legal basis.

What is a basis: an actual traffic infraction — speeding, a burned-out tag light, weaving out of the lane, failing to stop — or specific articulable facts suggesting impairment.

What isn't: the time of night, the location, or that a driver came from somewhere alcohol is served. Those describe nearly everyone leaving a bar at closing, including sober people.

The first thing to look at is what the officer wrote as the reason for the stop. If that line is thin, everything after it — the exercises, the breath test, the arrest — becomes contestable.