I think the German text is simply an error, something the translator missed. I didn't understand a word of what he said, but I think it has something to do with leaving the refridgerator open (at least that's when it happened for me). The guy in the bed is another error, basically the game tries to run the intro with Zak getting out of bed again, although he is already standing in the room - you will also notice an issue with opening the shades again.
Edit: I think Cairo was just something left in there from an early stage of development. They already had the graphics for the intro, so why not reuse it and let Zak visit again. If you've played the German version, you'll see that they have a bunch of other airports (locations from the original game) that you can't leave. Wisely they removed those when they updated the game for the translated version.
Edit: I think Cairo was just something left in there from an early stage of development. They already had the graphics for the intro, so why not reuse it and let Zak visit again. If you've played the German version, you'll see that they have a bunch of other airports (locations from the original game) that you can't leave. Wisely they removed those when they updated the game for the translated version.