You should read Vehicle Code Section 22517 which says " No person shall open the door of a vehicle on the side available to moving traffic unless it is reasonably safe to do so and can be done without interfering with the movement of such traffic, nor shall any person leave a door open upon the side of a vehicle available to moving traffic for a period of time longer than necessary to load or unload passengers."
I suggest you speak with a licensed California attorney who has experience with these types of cases.
A person must open his door on the side of traffic only when it is safe to do so. However, if you were driving to close to the parked cars, you also could be at fault. So it depends on the facts of the case.
The response given is not intended to create, nor does it create an ongoing duty to respond to questions. The response does not form an attorney-client relationship, nor is it intended to be anything other than the educated opinion of the author. It should not be relied upon as legal advice. The response given is based upon the limited facts provided by the person asking the question. To the extent additional or different facts exist, the response might possibly change.
If you were in the normal flow of traffic, and the other party opened their door while you passed causing it to collide with your car, then the other party is at fault. Let your insurance handle this--give them all the information you have to support what you were doing, and where you were at the time of the impact.
Sign up to receive a 3-part series of useful information and advice about personal injury law.