I'm not a huge fan of CBS, but I'm of the camp that thinks they didn't rip anything off. I learned about tardigrades from Animal Planet shows and other such science entertainment at most like four years ago. I thought, 'Hey! What a cool animal!' I'm thinking this guy had the same thought around the same time, but with the addition of, 'I should write a game about one!' in which he uses some science fiction-y ideas (which were likely gleaned from a love of science fiction, like say, Star Trek) and the color blue. Totally within the realm of possibility that a writer would come to the same conclusion, but within a script...borrowing ideas from previous Star Trek. If one can accept that possibility, then the similarities between the two products look more and more like coincidences. I think that's way more believable than any of the writing staff even KNOWING about this game.
I'm sure this guy truly believes he got ripped off, but I doubt that's what happened.