He isn't spawning vehicles. The NRG was already behind that wall (you can see the little dot disappearing when he jumped on it and there's 2 dots at the start of the video). The heli is just appearing there because it was there in someone elses screen (someone probably jumped out of it while flying, and due to SAMP not being perfectly synced, it ended up on different places depending on the player). In your screen you can see it sliding down the road on the minimap, before Germ pushes it which forces an update and updates in your screen as well.