A good in the goofs

I was reading the goofs and noticed a mistake. Here goes. The particular statement that I'm referring to is listed as a factual error concerning Tyrese Gibson's character. The statement says that he is referred to as a master sergeant but his rank insignia indicates otherwise. It also says that the master sergeant rank is an E-7 pay grade. I have to say, that is absolutely wrong. Master sergeant is an E-8 pay grade. There are two ranks in the E-8 grade and those are master sergeant and first sergeant, the latter being the command rank of that grade. It also says that his rank insignia is an E-9 insignia calling that rank a "Chief Master Sergeant." The army has no such rank. The only rank where "Chief" is used is the warrant officer ranks, which is WO 1-5 pay grades.
I feel that if you're going to claim a factual error then you need to know your facts.