I'll forgive you for not reading all the WND article. It's a joke of a news source.
However, to answer your question, nobody in the Vatican showed it to him. He was not shown the 3rd Secret. He was shown a supposed copy of it. That is, not the original.
And who showed it to him? Well, here's what the article says:
"While at the (Second Vatican) Council, I was given the text -- the supposed text -- of the third secret of Fatima," Fr. De Pauw said. "Journal reporters -- journalists -- gave it to me" and a few others in attendance.
Bold emphasis mine.
Get the picture?
A group of reporters approached him and said "Hey, wanna see the 3rd Secret?"
Typical WND trash, although not something which would bother the FR "Whack Pack", of course.
**Typical WND trash,**
Tend to agree with you. Secular site.