Simple goofs or 'Ed Wood Stupid' type of mistakes?

Under the goof section, there is mention of the confusion where the movie takes place. The cars have Georgia plates and I am pretty sure that is where the story is supposed to take place but everything relating to the prison screams Louisiana. I know the movie was filmed at Angola. The patches the guards wear look like Louisiana, not only in shape. I found a site that shows D.O.C. patches from each state and found this patch from Louisiana. It looks very similiar to the movie's patch without the GSP (Georgia State Prison?) rocker patch above it.

http://www.correctional-patches.com/statedoc/louisiana_doc_state_shape.jpg

Why bother to put the GSP rocker over a patch in the shape of Louisiana, that is Ed Wood kinda stupid? Was this a goof or did they just not care? I am not going to get into the brilliant idea of having BBT clean the blood of her purse, so she would not be upset and then give her a ride home in the car with the white leather interior.