Ah, Richard…I think InterNACHI is the highest authority. 
InterNACHIEC
This is an image from Indiana Residential Code. The drip loop is clearly larger that 12”, it’s even bigger than the door.
Alert the state of Indiana of their shortcoming?
Who measures drip loop? If it is configured correctly and looks like it will perform (keep water out of the mast head) 
I agree with Bob. The NEC provides no minimum length. A quick eyeball should be good enough to determine if water can travel up the conductors into the weatherhead.
The answer to the question, “Where do Home Inspectors come up with this shit?”.
From BAD graphics created from supposed technical experts, such as accredited on-line universities!!
I think KISS applies here.
Credit to the image
Absolutely, but don’t forget about high wind days, which can and will blow rainwater up the conductors and into the weatherhead… even with a proper drip loop!
I can only assume this is the case for InterNACHI suggesting/requiring a 12 inch drop.
(Remember, InterNACHI is focused on Florida right now)!
Image and text updated again: Drip Loop. - Inspection Gallery - InterNACHI®
