The answer query post isn't the same as the first posted question query. The 2nd post has an 'ELSE' statement which translates the results to -1. If you run the query in the answer post, you will get -1 instead of nulls.
Yep, I got this when I ran it, not the answer posted in the email. I only looked here because the posted answer looked wrong to me. -1 123 -1 20180301 -1