The original Nakamoto paper states
routine escrow mechanisms could easily be implemented to protect buyers
What is meant by "routine escrow mechanisms"?
There are certain sorts of escrow that are very difficult to implement without a trusted party. For example, an escrow system that only sends along the payment when the seller has provided proof of shipping would be impossible without a trusted third party.
However, if we change the escrow system a little bit, then we can implement it without a third party. For example, suppose we say that the buyer and the seller merely need to agree about where the bitcoins are sent. That is something that a decentralized network can check for.
We can use Clearcoin type mechanisms for this . ClearCoin is an escrow-type of service that allows safer payment by securely holding coins in escrow until both buyer and seller are satisfied. Sometimes there is a risk that a buyer will be unhappy with a purchase but no recourse is possible because Bitcoin transactions are not reversible. An escrow allows the buyer to send payment to an intermediary and release the funds only at such time the buyer is satisfied with the seller's level of service.
More details about Clearcoin can be found at this link.