I've seen a number of TAF cabs that have the one sideart reversed. If I were to guess, I'd say that when they were building the lower cabs, at some point, something happened to the set of screens typically used for the left side. Either they needed to be replaced or they got damaged somehow. Because they were making TAFs in such massive numbers at the time, they couldn't afford to lose a day or two(or maybe more) of production and just decided to print the right side then flip it over and use the same screens on the left side.
Remember, there wasn't too much going on at the time with respect to production accuracy with the cabs. There are a good number of cabs that had blue TAF art for their backboxes and gold art for their cabs:
https://images.pinside.com/2/9a/35/29a35c8cf48be32ef1abbc0f55d71da23adb8f36.jpg
I don't think they worried as much about accuracy as they did just getting as many games out the door as possible.