The tow was about a foot above the water and was essentialy invisable in the boats wake. The sheriff's department maritime police said there is no requirement to flag the tow. Also a tow is a right of way boat and a sailboat is a right of way boat so did not know in this situation which one would be burdened. I guess the insurance companies will have to fight it out.
International maritime law requires a signal, at least that was what they teached at maritime basic officer training 13 years ago. During night, he should have shown two white lights for a short tow, at daytime I think it is two black diamonds to signal the length of the tow.
If he speeded up to pass in front of you, he should also have given sounds signals when he realised you was in danger (5 short blasts I seem to remember).
Maritime law is very well organized, and cover most situations. Unless you have some local rules overriding international maritime law, it was not your fault, unless he flied the proper signals and gave sounds signals as you approached danger. I would have checked it out as you had substantial damage.
Sorry to hear about the damage to your boat, but good to hear that you was not injured worse!
