No other roof contractor would testify against the bad apple.

My employees had to take days off to testify.

I've worked in the roofing industry for many years and can testify there are many reasons why a TPO roof may actually be your best option.

If he threatens a lien, he has to testify that he completed the work to specification; lying would be perjury I believe.

Not too many people are testifying how it helped them make money.

I have a potential deal in the works from meeting someone that night, so I can testify myself to this.

Offering the statement of a party not testifying to prove the truth of the statement is called hearsay and is not admissable in court.

I don't see why though if you are able to get pictures (assuming I'm even allowed to take pictures) and you have another witness willing to testify.

I was trained by excellent mentors & had to testify many times when something went South. 

If you don't have a recent arms length transaction, or the hearing is expected to be contested because you're asking for a large reduction in value, you can hire an appraiser to prepare an assessment of value and testify on your behalf.