Any journalist who approaches innocent staff rather than going through "proper" channels (ie: contact company management/
PR reps) is clearly not having a care in the world about how badly he's trying to drop you into the dirt. These people are vermin and they're trying to bite you..so why be nice to them? Put a brick wall between you..tell him to take a hike and don't even help him by offering info about who to contact..let him do the work himself. Every piece of dialogue you offer can be published the next day.. eg: ."the staff we spoke to didn't even know the correct phone number for us to call..." etc.
I'd rather tell my boss that I told the press to go away rather than enter into any discussion whatsoever about who to call, how to contact..etc...then at least I'm blameless for any rubbish which is printed.