Is Tenant Responsible for Water Damage Repairs

[Ian Lanphier]

State: Texas

Situation: The AC unit inside the house leaked causing damage to flooring and drywall. The root cause of the leak was that the outside drip hose had been raised and pinned up against the wall not allowing normal operation. The tenants claim they know nothing about it but do have a lawn service hired. It seems quite likely that the lawn service adjusted the hose so they could mow and then forgot to put it down. We had the AC unit serviced about a month ago and it was operating normally. 

Our Lease: (2) Landlord will NOT pay to repair the following items unless caused by Landlord's negligence:

                          (a) conditions caused by Tenant, an Occupant, or any guest or invitee of Tenant;

Question: Should the Tenant be responsible for paying for the entire damages, paying the deductible on the home insurance claim, or not responsible at all?