Crashryan, I agree with you! In my case, I have a copy of Robotmen of The Lost Planet (Avon). An old Overstreet I have (1989-90) says the 3-page story at the end of that book is by Kinstler, when it is instead by McCann, and I was corrected by you on that score in 2017 in the Comments. So perhaps older Overstreets may be the source of these errors in attribution. Indeed, my 89-90 Overstreet incorrectly credits Kinstler with the Blue Gorilla story, but the 2017-18 edition says "Blue Gorilla by McCann?" with a question mark.
Link to the book:
White Princess of the Jungle 5