Front aluminum valve cover of V6 engine developed an oil leak. $1000 repair found a hole (melted?) in the cover beside center plug/coil. All three plug/coil holes are distorted more oval than round. It like the aluminum was softened by overheating. Parts replaced were valve cover, various gaskets & V-TEC valve. Any idea what could have caused this peculiar failure? I have photos of the cover (inside & outside views). This vehicle has 70k miles on it. Thank you.
Did you drive around Area 51 by any chance? 
Are you sure parts are aluminum, not aluminum-colored plastic?