Autistic people, who have service dogs, use the elevator only with their service dogs with them. That’s the tip. The dog can even call the elevator, press the button for them. But they go up and down together. I will record a complete video of the solution and post it on my modest channel.
The solution in the last video: http://twitch.tv/RickGalasio
PS: I loved your game and I’ve evaluated it.