I'm afraid I cannot agree with East Coast Girl here. I do not believe that NBC would tell the guys about Erin's prize. If they did, the guy would know (or figure out) that by choosing her (over the money), he gets to share the money!!!
Not that I'm a Conspiracy Theorist or anything , but I'll give this one a shot.
Occam's Razor - let's get simple about this.
Rob is simply there to be the one to offer the money to the guys, money that one of them takes. He may also be the one to tell them that it's love OR money (they may tell them earlier than they told the girls in FLOM1).
I just don't think Rob's role is a big, earthshaking one.
Also, NBC is going to have to put up the cash. Chances are anyway that the winner will take the lump sum, not the annuity, and likely would have to pay out less than $1 million, even to Erin.
Contradictions don't exist. If you are faced with a contradiction, check your premises. You will find that one of them is wrong. -- Ayn Rand, Atlas Shrugged