I had a similar experience recently.
I was on a semi-rural road and took a right turn, from the shoulder, onto the 6' wide shoulder of a major hwy without stopping at the light.
County Sherriff pulled me over, and wrote me up for failure to obey a traffic control device.
I protested that I wasn't even in the roadway itself and was 4' from the lane of traffic.
He responded that it doesn't matter.
I acknowledge that technically he is right, but I thought a little more discretion should have been used on his part as I wasn't endangering anyone.
Funny part was as he was writing me up, someone drives by and yells, "Oh come on.....get real!"