First off....David does have an account here and is more than welcome to come and defend himself and/or his business anytime he wishes.
Secondly....name-calling is still against the rules. In the past we have been tolerant of "scumbag" because there are a few individuals out there that are pretty much universally agreed on to be scumbags. But that is not the case with David or Reptster. If you (being the "universal you" and not just the individual being quoted) wish to express your opinion about his personal integrity or business practices, you are more than free to do so without resorting to name-calling.
Fair enough...David is untrustworthy and a liar. He won't defend himself here because he has no defense.