Inspection Report Question

[Alexander Gill]

I am in the process of completing the sale of a multi-family property. I accepted an offer with the standard inspection contingency. Buyer's inspector viewed the property yesterday. The buyer was at the inspection and walked down to talk to one of the existing tenants, under the pretenses of offering to keep the tenant on as a rental once the sale was completed. 

During the course of the buyer's conversation with the tenant, the tenant relayed some information about plumbing repairs recently completed. The buyer is now requesting additional plumbing work be completed to determine if there are any lingering issues. I am refusing  the additional plumbing work because the inspection report has not yet been completed, nor shown to me as justification for additional the plumbing work due to the inspection turning up a serious defect. Secondarily, the actual inspection conducted by the inspector, at least the verbal conversations relayed to me by my broker who was present during the inspection, did not find or prove any plumbing issues.

I am refusing the buyers request for the additional plumbing work, to me, the buyer agreed to provisions in the offer and is now trying to waive or get around those provisions to renegotiate the price. Buyer also is using the purchase as part of a 1031 exchange process so he is up against a deadline.

Looking for anyone who has experience or guidance on how to handle this without tanking the sale.