Yeah, the "being quiet" was a good choice on your part.
The law in AZ is pretty similar to what is going on in Idaho, plus it sure souns like this officer was uninformed about wakesurfing in general.
There are two areas on AZ boating law that deal with this issue, both in Article 5. I have listed the URL for the law and then also 'cut 'n pasted the applicable sections: http://www.gf.state.az.us/pdfs/inside_azgfd/all_azgfd_laws.pdf
ARTICLE 5. OPERATION OF WATERCRAFT
5-341. Negligent operation of watercraft or water
skis; restriction in operation of
watercraft; violation; classification
D. No person on water skis, a surfboard or a similar
contrivance shall behave in a careless, reckless or
5-346. Water skiing
B. The operator shall observe other watercraft traffic,
swimmers and hazards and shall not tow a person
or persons on water skis, a surfboard or similar contrivance
so close to other watercraft, swimmers or
structures as to constitute a hazard to life or limb of
Almsot always chatting with the officer or his immediate supervisor can help rectify any misunderstandings.
Under 5-341 you would need to establish that you weren't operating in a negligent manner. If the only issue was the proximity of the rider to the boat, and the concern, as expressed by the officer of a sudden stop by the operator you can esaily establish that what happens with wakesurfing is that the wake itself hits the back of the boat - usually pushing the boat forward, but also lifting the rider up and onto the swimpad - I know, I've done it.
While there is a risk of hitting your head on the boat, this very same risk exists with riding a PWC, or wakeskating, so that would seem to not be presumed negligent operation.
As regards 5-346 B, since the boat is moving away from rider, it would be difficult to understand the issue involved here.
Things to remember are the prop is up and under the boat, plus there is a swimdeck between the prop and rider, making wakesurfing one of the safest sports in existence.
I will find the NASBLA model law for you that has the reference to the relative safety of wakesurfing and I am sure that a calm, informative discussion with either the officer, asking for clarification, or with his immediate supervisior, you'll find the issue resolved.