Well, it's a little more than that. Lignite is a big no-no. You absolutely should rinse your pelleted carbon, but even then fish that are generally susceptible to HLLE showed trace affects of HLLE with the use of rinsed pelleted carbon. The big unknown here is whether the quality of the pelleted carbon used at the Toledo Zoo was of the same "high quality" that is used by the typical reef hobbyist. The general feeling is that since the zoo buys carbon in bulk that the quality is lower than what is purchased by the typical reef hobbyist, but I'm not sure that is a valid conclusion (i.e. how do we know that we're simply not purchasing the same carbon at a higher price in fancy packaging and being told that it is "high quality"?)
Maybe this is jumping to conclusions, but if I had a fish from one of the species listed (which I don't) and I cared about whether that fish remained healthy, I'm not sure that I could continue the use of carbon after reading this article. But, if nothing else, I would most certainly use it sparingly, would rinse it extremely thoroughly, and would not use it in a high-flow reactor.