Plot hole: Blind Master can sense when a person is lying. When Snake Eyes admits he is not pure of heart he explains this is because he is driven by his desire for revenge on his father's killer, which Blind Master reads as a truth. However, this is still a lie: a lie of omission. Snake Eyes is only telling part of the truth and omits the fact he is betraying the clan on Kenta's behalf to get his revenge. Snake Eyes is being deliberately deceptive, which is the definition of lying.
Other mistake: While Snake Eyes is fighting at the beginning of the film, the other guy throws him to a block of concrete. Snake hits on his head and should be dead by then or at least seriously injured.
