I'd like to make a couple of preliminary comments. I know Mary Richardson. I've served on committees with her in the past. The videotapes she's talking about are the ones that we have not been able to view, but that, we have heard, do show infractions. So we may well agree with her in what she's saying there.
As far as what constitutes a “humane” death goes, the definition is widely accepted. This is what you're talking about in slaughterhouses, with research animals, and whatever. It's a rapid, irreversible--irreversible is important--loss of consciousness followed by death. Usually bleeding is the way of confirming the death.