53. My Head 1
When Trinity throws her knife that then goes on to embed itself in a soldiers forehead, as he falls to the ground the knife wobbles like it might be fake or made of rubber or something.
52. Double Glazing
When Neo is shooting at the agent who jumps out of the helicopter, the agent dodges all the bullets doing his Matrix thing. But as the bullets pass him, they also appear to do no damage to the glass building behind him.
51. Going Going Guns!
It's easy to forget how awesome the above scene looked in 1996, people were blown away when they saw it. Everyone was speculating on how the Wachowski's did it and the world went bullet-time crazy. However, the scene does contain a mistake. Neo drops his guns on the floor and they land on either side of him. As the camera goes around him, there are no guns visible and when he hits the floor, they are next to him again.
50. Is She Hiding?
If you thought the guns disappearing was bad, what happened to the soldiers that just got brutally taken down? And where has Trinity gone because as the camera swoops around Neo, none of the bodies are where they fell and Trinity appears to have gone for a sit down.
49. Direction Of Impact.
The angle Neo gets hit by the Agent's bullets, it leaves a vertical mark on his shoulder. But when he stands up, the wound is horizontal.