So I sold a coworker my old harmony 800.1 amp for 50 bucks. I tested it before handing it over and everything worked as it should. He had subs in his old car and didn't ask for any tips/help wiring this one up. He ran a bad ground plus arced the power wire several times trying to hook it because it was still live off the battery. Now the amp sounds like trash and I don't think it's making anywhere rated power like it did. He hasn't asked outright for his money back but he's definitely hinting at it. I really wanna tell him he's burnt since all he had to was ask for help. Am I out line?