Analysis of Casino Shelf Shuffling Machines by Stanford University.
Decide for yourself.
If any of you have any insight to the New Jersey Casino Control Commission or the Nevada Gaming Commission, you would understand the huge downside to a casino doing anything whatsoever to the millionth power that would even be considered 'cheating' or 'stacking the odds by mechanical methods' in the favor of the casino. But hey, it makes for great talk and gossip how a machine is their cheating device.
And most casinos I know from several years ago, implemented the '2 times run through' for new decks of cards. And that explanation is contained within the attached also.
http://statweb.stanford.edu/~susan/papers/casino.pdf