Well guys hello first cause this is my first post in the forum ! As for this weeks manga. I think that Neji is not a clone and i will explain.
First of all nejis killing spree is happening at the same night so Tomorrow as stated by madara is yet to come (Manga 538). That means that if his moon plan is going to be realised tomorrow its gonna happen tonight right ? Then notice that neji looks at the moon and then passes away. Sign of being under Genjutsu or at least a mind controling technique ??? Moreover when Neji kills the first Medi Jonin there is a picture of the same moon again. Is it coincidence ? I dont think so... I am pretty sure Neji is the first victim of The great Moon eye plan. Sakura also said that the spy must be under a powerfull technique. At first i thought that Itachi was behind the Genjutsu cause of his appearance but then it became clear when i saw that Neji is always followed by a... moon

Finaly, if it was a Zetsu clone the Ninjas who scaned him at the entrance would NOT be able to find out but, what about Kiba ??? I dont think that Zetsu can copy the scent too ... It is stated thatKiba is a sensor too at the begining so if something fishy would happen he would notice by the scent !!!
As i noticed when trying to post the reply i can not post links in my first post... but if you want you can check it for yourself