Not sure what you mean by "is this accurate?" There are a number of different regulations that come into play here and it would require some research to uncover the answer. But frankly even if every lawyer who responds tells you that this was improper it doesn't do you any good. You should probably have a lawyer review the documentation and advise you on the road forward.
This post is for information purposes only and does not constitute legal advice, nor does it establish an attorney client relationship with Mr. Cassara.
Once an evaluation is filed in a servicemember's permanent personnel file, it is presumed to be administratively and substantively correct. Thereafter, the burden of proof rests with the individual servicemember to provide evidence of a clear and convincing nature that the statements in the evaluation are untrue or unjust, in whole or in part, thereby warranting removal. Additionally, if a rater does not follow the regulation/order for evaluating a servicemember, he or she may be able to have the NCOER removed. I can help your friend appeal the evaluation to have it removed from his record. Good luck.
Here's my take on this issue. In a hyper technical sense yes it's the rater's time that matters. The reviewer can change without affecting the rated time. But a 90 day change of rater is optional. That time could be dead / unrated time but most units will try to minimize this unrated time. It's not technically correct to fold in that time. But units do it all the time and often to the soldiers benefit. I do the same thing with NCOs I rate as a reservist. In the end all that matters is your rating. So be careful what you ask for. No one NCOER is a career ender except a relief for cause. But getting the rep around your unit as a walking IG complaint is worse. Pick your battles wisely.