Most likely the answer is "no", unless you knew that you should have not loaned your friend your car. If not, you are not liable, but your friend would be.
Generally, the owner of a vehicle is not responsible (liable) for the negligent acts of another person driving the owner's vehicle. Whether you have insurance or not does not create or extinguish personal liability. There may be other theories of liability against you that may or may not apply to your situation, such as negligent entrustment of a vehicle to an unqualified driver, but simply because you own the car involved does not make you liable for another person's negligence. However, if the police investigate further and discover that you, the owner of the vehicle, did not have insurance on the date of the accident, you may be at risk for a civil traffic fine for non-compliance with Arizona's financial responsibility (mandatory insurance) law.
Disclaimer - We have not created an attorney/client relationship. Please do not consider this legal advice addressing your specific case.
Sign up to receive a 3-part series of useful information and advice about personal injury law.