Floor Ruling WSOP: Hidden Chips

[po-Jay-to]

I was reading the WSOP live reporting thread on Pokernews.com and saw that one of the tournaments last week had a hand killed because the player did not have their high denomination chips visible. There were not a lot of details available within the post (I can not find the post after an extensive search) so it's difficult to determine if this was an appropriate floor ruling.

Does anyone have any additional info on this ruling and the circumstances surrounding it?