^Many good points made above by alabama.
But let me interject here for a second.
There is a way for the ecsrow agent to check if the moneypak code is good. You don't have to give a card number or any personal info.
If the escrow agent has a greendot card, he can go to their website and click "add funds via MoneyPak." Then, once prompted, the escrow agent can type in the code. If the code is good, something like this will appear:
"To verify, we will be loading $990 on the card number ending in 4321."
At this point, someone trying to load a card would typically click the confirm button, then the funds would be loaded onto their card. But, since the escrow agent is simply verifying funds, he would click cancel. This way, the moneypak funds are verified AND they stay on the moneypak.
The more you know.
Yes but once the escrow checks the code, the moneypak supplier could have that redeem page waiting for that exact moment of escrow saying good code and click the redeem button to load onto his own card. Now the escrow is set to believe the moneypak receiver has used the code.
Very true. BUT, if I were the escrow agent (I would also be holding the bitcoin) I would never tell the moneypak supplier anything. No need to unless the code is actually bogus. If the code is good, simply forward the code to the bitcoin seller, let he or she add the funds to their card or paypal, then forward the bitcoin to the buyer. Simple enough.
Of course, there is the slight possibility that some superman scam artist gets lucky and hits that "confirm" button at the perfect time. But, in the case that he is left in the dark until the funds have been loaded onto the seller's card, trying to scam prematurely will simply mean he is getting no bitcoins and he pretty much just went through a lengthy reload of his own prepaid debit card.