Very interesting find!

The screenwriter describes the scene as being an important part of the original idea for the script: https://www.brucejoelrubin.com/brainstorm.html

The biographical information about him on Wikipedia doesn’t indicate that he speaks Finnish, but he is well-traveled (though Finland is not mentioned).

I wonder if the scene is somewhat autobiographical and the song came from his actual wife?

I have emailed him. :-)