Validate buyer's intention to extend inspection period?

[Christie Zhu]

Greetings to you!

We are in contact with a cash buyer and had a 10 business days inspection period. After the inspection, we followed up for a week for the inspection results and didn't hear back from the buyer's agent.  We thought it may not go through and we sent the tenants docs(lease, screening, contact, rent roll) on the morning of the 9th day.  On the 11th day, they are asking to sign an addendum to extend another 3 days for reviewing tenants' docs, otherwise, they will cancel the contract.  

- If signing, they can walk away from the deal for whatever reason with the earnest. 

- If not signing, they are threatening to cancel the deal. 

What would you do? 

PS: We are guessing it might be the buyer's agent who dropped the ball with being on vacation for one week without the internet and forwarded the tenant info late.