he alleges that the renter was aggressively argumentative, held rent hostage for minor repairs, left the apartment dirty and in disrepair.

Because that can lead to allegations of favoritism, and biased or colluded results.If I were walking in your shoes, I would mention the prior report (but not  the company or person), question the comps that were cited, and the FMV being reported.You'll get a fresh look at the property and hopefully a better result.

Hello @Philip Cameron and welcome to Bigger Pockets.

It was great to meet you last night in Cameron Village.

@Cameron - I will definitely will rely heavily on the background check and references.

@Ryan Cameron thank you and good to meet you. 

I agree with @Cameron Tope.

@Meleneal Cameron,I would leave the necessity of the chimney to professionals and Santa (Ho ho ho, hope i brought a smile) now what you need to get done is integrity/protection of the roof around the chimney exit point!

@Meleneal Cameron - The chimney is not the seller's responsibility, unless they knew of a problem and did not disclose it.  

@Cameron Norfleet yeah I know Cameron my posts were in response to the poster who was indicating that NOI is what determines value in a property.