Hideo Kojima himself is going to show a gameplay demo of the Ground Zeroes prologue of Metal Gear Solid V: The Phantom Pain at during a series of stage events at the Tokyo Game show, but he's running into a problem: apparently the enemies are so unpredictable that he can't really plan the presentation beforehand, as he explained on Twitter.

If you're going to see the demo at the stage event, I had to stop [before the end of the presentation] because of errors.

Oh my, it's difficult to do a 100% perfect run of the demo for the stage event. The behavior of the enemy is different every time, I can't help it because I cannot predict it. If I'm found out [by the enemy] while playing it may not be possible to complete the presentation as planned. If it was our own booth, extending the time would be possible on a case-by-case basis, but this time it's not.

Considering that the biggest flaw in previous Metal Gear Solid game was (at least in my opinion) that the enemies were way too predictable, this is a problem I can easaily forgive. As a matter of fact, I'm quite sure a lot of developers dealing with poor AI would love to have to work around the same issue at their own presentations.