user3837: The original Nakamoto paper states

routine escrow mechanisms could easily be implemented to protect buyers

What is meant by "routine escrow mechanisms"?

user2306: 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.

3837: <p>The <a href="http://bitcoin.org/bitcoin.pdf" rel="noreferrer">original Nakamoto paper</a> states</p>

<blockquote>
  <p>routine escrow mechanisms could easily be implemented to protect buyers</p>
</blockquote>

<p>What is meant by "routine escrow mechanisms"?</p>
 2306: <p>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.</p>

<p>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. <em>That</em> is something that a decentralized network can check for.</p>
