I can say with confidence that this sort of thing would never occur in a modern research laboratory. Note that standards for ethical experimentation on animals (including humans) hadn't really appeared until the 70s and 80s. A couple of points here: Any type of animal experimentation must be accompanied by an IACUC protocol that is approved by a committee, typically at least 3 people, and usually including a veterina…
I recently completed my doctorate in Pharmacology and I have a Home Office license to perform specific surgical procedures on animals. I have training in surgery, anaesthesia and euthanasia which is routinely assessed to maintain my Home Office license.
The details of the experimental protocol that the poster lists - deprive resource, validate behaviour and reward - are probably correct, sensationalised, but correct. I say that, because this reads like the sort of pain protocols I have been involved with in the past. The simple fact is that to explore whether a pain medication works, you must inflict pain, see whether your drug modifies pain behaviour and repeat to sufficient statistical power.
The details of the experimenter dispatching (killing, euthanising ...) the animals with chloroform, en masse, in a plastic bag is a violation of his license and his colleagues license, it is not a listed method on Schedule 1 Method of Euthanasia. It is one of the facets of animal experimentation regulation that I am proud of, the humane killing of animals ensures minimal distress. The euthanasia regulation for animal experimentation are stricter than those in the food industry and far more stricter than the exemptions that religious faiths have when preparing meat.
Non-vertebrates animals are covered by the ASPA 1986 guidelines in the UK for euthanasia and commonly you must present an anaesthetic regime for all uses of laboratory animals. Octopuses are explicitly named as they are one of the oldest laboratory animals in use — they were pivotal in understanding the role of ions and ion channel pumps in nervous transmission.