It would likely be sufficient especially due to his/her observation of three hits. At least your parking skills will save you a parking ticket and potentially it could be pursuasive evidence that you were not impaired.
The answer is MAYBE. In Pennsylvania, that would certainly be enough for the police officer to inquire if everything is alright (No suspicion needed, whatsoever). If, upon contact he/she noted the odor of alcoholic beverage, saw glassy eyes, heard slurred speech, or encountered disorientation, that wold certainly be enough to request that a person perform a field sobriety test. A failure of a field sobriety test would give rise to the administration of a PBT (Preliminary Breath Test). If this were positive, you would be arrested and a certified breath test performed.
Assuming that the didn't just pull you out of the car and arrest you after the minor bumps and they went through the above procedures, then the arrest was proper. (That does not mean it can't be challenged, legally) Also, if you were over the legal limit, you can still possibly get ARD (Accelerated Rehabilitative Disposition) if this is a first offense. ARD requires a guilty plea, but the matter will get dismissed (Your record will stay conviction free) after a set period of time (6 months or 1 year) You may be able to enter ARD do that without an attorney and save the legal fees for all of the fines you will have to pay.
The attached comment is for informational purposes only. It is not a legal opinion and no attorney-client relationship is being entered into. Should any person wish legal advice, they should contact this attorney at his office and enter into an attorney-client relationship via a written contract, which terms will be fully discussed to client's satisfaction prior to entry.