For some LFS it would be fair to be critical but this is a difficult industry and still relatively new (artificial salt has been commercially available for less than 60 years and SCUBA diving for the general pubic began in the early 1950's). To do business, most have to buy from wholesalers and more or less take what they get. Many educate themselves quite well but still may receive animals (or have a request to fill) where they have no knowledge of the needed care for survival.
There is a lot of criticism for the way the industry is run and we may be seeing some unwanted regulations (vs education and voluntary changes) in the near future.
In 2009 a bill was proposed that would have pretty much shut down all imports to the aquarium (as well as other animal related) trade. That bill was defeated for lack of definition (if passed it would have pretty well shut down all but special case live stock imports without identifying any need to block shipment. Proof of harmlessness - the bill was proposed to stop invasive species, not because of animal loss but losses were presented as a point of promoting the bill - would have to come from anyone wanting to sell each individual species) but the pot is still smoldering and we will see new legislation proposed, likely next year.
Housing, keeping and selling aquarium livestock is a moral tightrope walk. Some of us feel that the aquarium hobby promotes and exposes a greater awareness of the fragile nature and interaction of our environment and the relatively small loss caused by our involvement is countered by our change in understanding and promoting ocean awareness, others find the hobby more destructive than educationally beneficial. When I meet young people that have an addiction to watching nature shows instead of mindless (or worse) cartoons or that can tell me facts about the ocean and some of its critters (most of these discussions are well beyond their parents' knowledge), I can't help but believe that hobbyist have lead the way to making the ocean and its creatures interesting and a topic that is now entering schools and homes with more than just facts about melting ice.
I tell a story about a pair of kids racing around our under aquarium tunnel looking at all the unusual animals. One of the boys stopped and loudly said something to to the effect of, "COOL, what is THAT?" to which the mother promptly collared the young man and said, "THAT is why we don't go into the ocean" and marched him to the end of the tunnel. The humor in the story was that all the people that were with me immediately stopped and in unison turned to look at me to see what I would do as I would normally have offered an answer to the initial question. After wincing at the mother's reaction, I realized the kids were probably going to be "OK" and I think it is outside exposure that makes it that way.
So how does my rant tie to the LSF ? If the store (and Seamay has vouched for the knowledge of his LSF) is providing educated understanding of the marine environment to its customers then I don't think irresponsible applies (there is a pet store near me that is not this kind of seller). Hopefully Seamay will report back to the LSF on what happened to the octopus and what he has learned about our unusual pets. I recommend this for any animal that does well or does poorly if you have a regular supplier. Your personal feedback helps them make better choices, and in some cases, require that the wholesalers NOT send them certain animals.