For sure let the agency know about the abandonment and/or misuse.

In this case, if the Tenant complains to the Housing office that you won't make a particular repair, even if a reasonable person could determine it needed repair due to Tenant misuse, the Housing office can withhold payment until repair is completed AND they inspect and approve the repair.

Warranty will not cover misuse or damage.

It's a tactic that is often misused, but it depends of state statutes and what is allowed.

This term is misused a lot!

Unless it is obvious tenant misuse that caused the mold, I would of done the testing myself as a landlord and eaten the cost. 

I think whenever real estate heats up, a lot of strategy are misused because of poor training.

Not only are the an often misused in marketing, they really don't provide THAT much value.

I apologize if I misused the forum.  

Aloha,First, your Rental Agreement should clearly state that Tenant is responsible for stoppages in plumbing fixtures or lines due to misuse or abuse.