OH, it sounds to me like he answered the question. He got an email from them about a job and wanted to know if you knew them. I don't see why you would be upset at this. What more did you need to know? It sounds like nitpicking to me.
Don't go shaking the [Bleep!] tree and expect an angel to fall out.
Liars lie and cheaters cheat...know it and don't be surprised. Protect yourself.
