We have a zero edge pool thats maintained by a company. On Friday it was serviced and the tech left it on backwash!! The bottom catch basin was completely empty when we found it Sunday! its on a timer to come on for 8hrs every day. He said theres probably no damage but i thiught that would 100% destroy the pumps. what does everyone think? i dont know allot about pools but i want to make sure hes liable for damage! thank you