This is on me for not having the appropriate lease language in place, so I have to figure out how to fix it.

We have language that lease is not valid until receipt of deposit.

Some propose buyouts, Some walkaway, and others have sneaky language in the lease that let's them off the hook. 

After the date of the option, the language in the contract will usually state that the option has expired and buyer's rights terminate.

No language requirements.

If you have the right language in your contract, you don't have to give any explanation to the seller about why you are canceling or getting written approval from them.

Is there specific language I could look for in the lease agreement that would let me know if that is the case?

It’s part of the agent's duties to make this clear in the purchase agreement or the buyer's brokerage agreement.Clarification: The broker you met with was likely emphasizing that, according to the letter of the law or the standard contract language, the buyer is technically responsible for their agent's commission.

You can incorporate language into the sales agreement that allows you to form an LLC and take title in that LLC as a closing condition.

They should also be able to speak the language or at least have a worksheet to figure out your numbers for you.