James, legislation can't fix stupidity!!
Each of the examples you provide (my favorite is the one about the fossil....) seem more to be evidence that in the absence of any common standards of acceptable practice, individuals will act in ways that they think are best, and at times make (understandable) errors. Yes, double-standards are a problem, but one of my arguments is that regulations help prevent personal, uninformed decisions that might be harmful to the animals.
More generally:
I think it's worth noting that the primary intention of most IACUC regulations is to facilitate, not hobble, research - to ensure that research - if it's going to be done at all - is conducted on healthy, appropriately housed and properly husbanded animals. They are usually staffed primarily by scientists, veterinarians and one or two non-scientific outsiders. They are not anti-research.
As to Greg's question:
Why are these regulations warranted? Are there scientists and institutions doing some off the wall experiments? Or aquariums caring for their cephalopods poorly? I personally have seen octopuses (bimacs and briareus, mature size) supposedly being used for 'learning' experiments that were housed in completely bare 12"x12"x12' plexiglass boxes, without any shelters, little room to move and under constant bright lighting with no shielding from people walking past - not overtly inhumane or cruel, but almost certainly stressful, boring and suboptimal. It is well established that for rodents, a properly enriched and appropriately appointed cage makes for not only better results, but happier animals. For octopuses, why not require the same standards? (for toxic species, different housing is of course necessary to balance the need to keep researchers safe - this is something that IACUCs regularly account for with vertebrate disease-models). If your experiment for whatever reason needs isolation, sensory deprivation, stress, pain etc., and you have valid reason for doing that to your subjects, it is the job of the impartial IACUC committee to see to it that an appropriate balance between individual welfare and overall benefits are optimised. Why argue with that?
The concern, often expressed, that the people on these committees are not well enough informed to make a correct decision on the value of the study or on what is best for the animal, can usually be overcome by in-person discussions between researchers and the panel. A related misconception I see growing in these discussions is that "The Government" somehow oversees the approval process for each study. This is, of course, not the case. The 'government' will appoint some body to devise the regulations, most likely made up of scientists at the NSF or NIH, and follow what they recommend. Not that scientists can't also do a crappy job of writing recommendations, of course... Once the recommendations are legislated, each institution uses it's own approval committee that is charged with applying those regulations.
In institutions with researchers working on inverts, those committees are going to be staffed with people familiar with invertebrate animals. It's not some random be-suited guy wearing a donkey or elephant pin, in an office in Washington, whose going to refuse to approve your application.
Note that all my focus here is on research settings, not hobbyists or private keepers. General animal welfare laws are an entirely separate beast from research animal welfare laws. (Can anyone confirm that the EU directive does not cover private owners?).
Of course, the main issue to me is that the EU has applied its directive in the absence of any data concerning pain or suffering in cephalopods. The reference they cite for evidence of 'pain sensation' is a review article that does not provide empirical evidence of this. If regulations are to be drafted, let us at least have some scientific evidence on which to ground them.