Plot hole: The entire plot hinges on the villain's gang obtaining the tablet that allows admin access to the building's systems. However, it can only be unlocked via facial recognition and it is keyed only to Will Sawyer's face. In fact, when they finally do get it, Xia unlocks it by holding it up to Sawyer's face. So what was the point of trying to steal the backpack containing the tablet? Without Will to unlock it, the tablet is useless.
Plot hole: Other than plot development, Why did Will Sawyer even need the tablet in first place? The tablet controls the building's "fire system" but he had already carried out of the building's analysis by then, and that also included the building's fire protection.