How did he have time to get all those diamonds out?
Can someone explain to me how he was able to spend that amount of time getting that amount of diamonds out of the vault without being seen by the security guard? At first he is at risk of being seen because he has to spend time putting the code in and opening the vault door and he is lucky because the security guard is distracted. But what was the security guard doing the whole time he was moving those diamonds backwards and forwards? How come the vault door is visible to the security guy when he puts the code in but then after it is not?
When the security guard is looking it just shows Michael Caine walking backwards and forwards with his cleaning equipment over and over again. The security guard didn't find it odd that this guy has been walking backwards and forwards in the same spot for hours? Nobody walked past the vault at all and saw the door open in all that time?