Alan.
I believe that this was one of the "new" rules introduced in this year"s TDA summit.
Basically, you cannot ask to see a hand for information purposes. Any request to see a losing hand is met with a call to the floor who should ask the basis for the request.
I"m waiting on the new rules to be published to confirm.
BTW..Harrahs" poker room has changed managers twice since 2008 so their "rule" may not still be in effect.