How is installing a new OS not a user action? Look, if you buy a piece of hardware, install software that damages it, and then expect to get a refund, you're out of your mind. The laptop was not defective, it was broken by the customer.
Who said it isn't? The issue is newegg said "no RMA for you because you installed an OS, we're not even going to look into the issue to see if it was related". Then they said "oh no, that rep just made a mistake, installing an OS is fine". But the reps doing RMAs clearly still don't know this policy, and still reject RMAs without even looking into them. I'm really not understanding why this very simple, easy to understand concept needs to be repeated over and over.