There are some possible ways:
1. Do nothing and high likely will lost.
2. It's become an extra bonus for the escrow.
3. Share it to every users who're involved.
4. Donation e.g. this forum, the one who needs etc.
This is only possible if both parties have no deal and the escrow has no terms about leftover funds, It's for the escrow party to address or not this issue because this is a deal of two parties involved, but the escrow party could send a message to the other party or make a public announcement here specifying a claiming period or they will consider this a lost fund and a lost fund is considered finder's keeper under specific time to claim the funds and can decide on what to do with the funds.