Other mistake: In the scene from Mako's memory, the terrified little girl stops crying and smiles when Pentecost emerges from the Jaeger's head/cockpit. But if the Jaegers are 250 feet tall, how could she possibly have seen him? It's not kneeling when she looks up at him.
Other mistake: Near the end of the movie, Mako swims to the unconscious Raleigh's survival, blows the top shield of his survival pod, removes his helmet and checks for a carotid pulse...while wearing gloves. No wonder she thought he was dead.
Other mistake: Right after Otachi sprays acid, Gipsy reaches in its mouth to pull its tongue out, but doesn't get affected by any.
Other mistake: During the triple event, different war clocks times are different. One that is stopped and the one that wasn't reset.
Other mistake: When Crimson Typhoon's head is pulled off, their location should not be visible on the radar behind Stacker.
Other mistake: The war clock during the triple event does not reset as it should when a Kaiju breaches.
Answer: Simple: because in a mere 14 months (as was said by Pentecost) they managed to build an effective weapon against the Kaiju.
Friso94