In FL, the amount of escrow money retained by the seller is usually defined in the listing agreement, and the balance is split equally between the brokerages involved. However, all is negotiable, and both buyer and seller has to agree to the split and release brokers of liability. If they disagree, our real estate commission decides the case - informing the brokers what to do. If the buyer or seller are not happy about commission's decision, the case will be decided through mediation.
Based on what other agents wrote here, check out both the listing agreement (if possible) and the contract. If needed further clarification, go see an attorney - for some, the 1st consult is free. I'd definitely talk to your agent and his broker - many issues are resolved by negotiating vs. courts. There are mediation companies, heart to heart talks...
Hope this helps,
Beachfront Realty, Inc.