In the 2006 Main Event, there were roughly 2 million more chips at the final table than what was supposed to be. I remember it being announced, and here is a blurb from a pokernews article from Feb. 2007.
Why has Harrah's not commented on the Two Million Chip incident? Well first of all they did. If you have watched the ESPN broadcast of the final table of the main event, about 7 minutes in you heard Lon McEachern say:
"If you're really quick with math, you might notice that there are more than two million extra chips in play. That may be due to a miscount during the color-up of chips so now... a little over 90 million chips at the final table."
Here is the link to the article:
https://www.pokernews.com/news/2007/...nths-after.htm
It says a formal investigation by the NGC found that 2.41 million more chips were in play than what was supposed to be. No prosecutions because of lack of evidence.