I was thinking about involving platform representatives in such situations, there anyway will be disputes that require a human to handle. But this would make the platform "centralized" at some level. We're brainstorming all possible solutions that wouldn't require human involvement.
Have you seen how Bisq works? I suggest try to look around how that whole application works. On the docs, there's also a mention of decentralized dispute resolution. Bisq is a decentralized bitcoin exchange that does not use smart contracts instead it uses a specific trading protocol. I believe if you take a look at it, it will somehow be able to widen your understanding if you really want to create decentralized escrow.