As a "warning ticket" with no dollar figure attached, I'm not too concerned about this ticket. I do know that by looking back through the mirrors, you can not see the mudflap. If the sun is right, you can get a look at the shadow it casts on the road, but guage the height of it while going down the road from that shadow, and you're better than I am.
Now, from the cop's point of view, if the lower edge of the mudflap is about the middle of the axle, knowing the height of the tire, he could say it's over 8" from the road surface. But, as to just how much over that it actually is while you're driving, he didn't even try to say. I've not talked to anyone that was fined for it, but it does seem as though they are using this to "get a foot in the door" to check anything and everything else out. That's where the tickets come from. It simply gives him cause to stop you, and the rest of your ducks better be all in a row.
What I would be curious about is, "does this affect the company's SAFE STATS"?