If you take control of an account prior to receiving payment then the identity of the account will leak to the buyer then the buyer could publish the identity of the account which would cause damage to the seller.
There are ways to make the transfer so that it isnt revealed. For example only changing after escrow has the coins in escrow address.
Even if not, its up to buyer and seller to negotiate on a security level they feel comfortable with. Escrow only should step in when its unsecure for him or to give a tip about a potential risk. But at the end its up to them to decide what they feel comfortable with.
It would also be that there could be a large amount of time that the escrow is in control of the account and it the account was immediately previously involved in something malicious then it may look like the escrow was behind the malicious activity.
I dont see that problem since its easily proven that the escrow isnt in charge.
Another risk to the escrow would be that the account could get banned while in possession of the escrow and there would be a question of if the escrow did something to get the account banned or if it was the behavior of the seller.
Then you might let the logins send to you only after the escrow address is funded. Its highly unlikely that it gets banned in the time after that.
A third risk to the escrow is what happens when the buyer takes a long time to pay. If the escrow is taking possession of the account first then there is an argument to pay the seller directly so there could be a delay in payment then the account would eventually get returned to the seller. If the buyer does not receive notification that the account is returned to the seller then the seller could end up with both payment and the account
Buyer funds first then. And why should the escrow release the coins to the seller before the buyer claims the accounts are secured?
If the buyer were to pay first then funds would be safe for the buyer in the event that the seller is unable to deliver. The escrow would be in control of the private key associated with the escrow address so he can refund the buyer in the event the seller cannot deliver.
I am saying that ponzis were able to more easily deflect questions about their ability to be trusted and let them say that everyone that's runs a ponzi has negative trust and is not a reflection on them specifically.
Might be that scammers are often virtuous with words. Though assuming that this here was a scam attempt sounds a far fetched assumption. Its not that he posted some "Double your bitcoin"-Links, where you know with certainty whats going on.
Edit:
You have no way of knowing if the account named by the seller is actually owned by the seller, or even if it is, you have no way of knowing that the seller will actually provide the password to the account once escrow is funded. That method puts the escrow at risk.
Then the escrow gives back the bitcoins. No risk at all. Since those things practically never happens, its not a risk at all. Even when, no harm done. The seller can get a red trust and thats it. If he later comes and claims he was in hospital then things can proceed.