BaconIsMyBFF

Stupidity: The Arashikage clan has sworn to protect the jewel and placed it in a safe that can only be opened with the blood of the family. This presumes that no-one in the family will ever have a change of heart, which is actually shown happening with two members: Kenta and later Tommy when he uses the jewel in the climax. It also presumes that the Arashikage clan trusts that none of their family members will ever have illegitimate children until the end of time.

BaconIsMyBFF

Stupidity: While Tommy and Snake Eyes are trying to escape the docks in the truck, the Yakuza men surround the truck and stab over a dozen swords in all parts of the cab. Not one of the men ever thinks to use their sword to slash the tires, allowing the heroes to make an easy escape.

BaconIsMyBFF

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.

BaconIsMyBFF

Stupidity: A lock which can be opened with your blood is horrible security. Leaving this as the only security measure on the safe, instead of also using a combination lock or other biometrics such as fingerprints, is done just so Snake Eyes has an easy way into the safe. A person's blood can be obtained through several means, most obviously by killing them, making this a completely unrealistic security measure.

BaconIsMyBFF