This is the most retarded theory in Naruto Base history. The Water Mirror is unique to Yagura therefore the 3 tails could not teach Naruto. Even if he could Naruto could not learn an entirely new technique in a few seconds, he isn't that skilled.
3rd, we don't have to prove anything. You are the one making random, nonsensical claims that are backed by no evidence whatsoever. That means you are the one who has to provide the proof, no one else. You're claiming Naruto can do a completely random jutsu that he doesn't know and has never used before while saying "Prove he can't or he can!". By your logic if I say Itachi can use Rikudo Senjutsu it would be up to you to prove that he can't. That doesn't make any sense whatsoever. This thread is shit.