He's not asking for a competitor. He's asking about the OE manufacturer so that he can make sure that he gets the right one. I'm sorry, but you're being completely ridiculous about the whole thing. There's nothing wrong with ensuring that you're actually getting OE parts. Just because a company says that a product is OE does not necessarily mean that it is. Humans do this thing called lying
It was a perfectly valid question. Why are you taking it so personal?