Art of the Steal: On the Trail of World’s Most Ingenious Thief (April 2010)
wired.com
wired.com
However, I tend to agree with you. The details (especially the "wow!" ones) are highly suspect.
EDIT: Oh wait, I already said that when this article was posted 9 months ago.
It's been a long time since I read this story, but there is a lot in there which has the feeling of being a tall tale. Like parachuting onto a roof in the dead of night, when he may just as well have bought a ticket and hidden behind a curtain somewhere in those 1000 rooms.
The replica didn't need to be perfect, just look similar. They don't take jewels out of their box every day to take a close look at hem unless they need to. He got that from the gift store.
You could find a pilot willing to drop you at night at the same place you find a parachute. Skydivers & and their friends are weird thrillseekers. They would do a night drop for someone because they thought it was cool. Blanchart didn't have to tell them the truth as to why he wanted dropping.
As for the vacation... that seemed to come first, and the robbery on a whim. He didn't go there planning to steal the star.
Considering artificial diamonds can already be made of a better quality and cheaper, diamonds are going to be reserved as a high-fashion rather than a consumer item. In other words, your grandma's wedding-ring diamond may be worth actual pennies if you ever want to sell it.
I have seen several episodes of "Master Mind" where detectives/judges would describe professional thieves with admiration.