By questioning "memory", Smokin is questioning the reliability of all human knowledge and the human thought process itself.
Under that condition, not only are Janet and Emma wrong!, all human knowledge is unreliable, and no so-called facts can ever exist, not just in the Cooper case, but in the whole human enterprise! This is no trivial matter! This is the very tool many are using to question all facts in the Cooper case ... except their alleged facts of course! It is one of the reasons we are here at this website vs another ... in the first place!
Some alleged facts:
If, by "memory", you mean recall of events, it is well established scientific fact that it is unreliable and imperfect. Taking this into account does not mean outright rejection or invalidation of all memories.
I did not see Smokin questioning the reliability of
all human knowledge. If she did so in the sense of
the totality of human "knowledge" rather than every individual bit of human knowledge, she would be correct. Look at everything everyone in the world "knows." Most of it is wrong. People "know" things regardless of whether or not the things are facts. Taken as a whole, human knowledge is unreliable (incorrect) in the extreme. The human thought process is unreliable in the extreme. Humans are imperfect. People come up with ways to rationalize things they don't nearly understand. Humans "think" at least as much with their feelings as we do with any logic.
Recognizing the limitations of memory does not mean Janet and Emma were
totally wrong. But we are
all wrong to different extents. Something happened that night, some of it somewhat "physics" in nature. They saw (perceived) something. What they saw was a product both of what really happened, the environment, and of their own natures. Then, it's all been modified by time and by other peoples' interpretations. Saying that much of what everyone remembers is not correct is not saying anyone is totally wrong, that
all human knowledge is unreliable, or that no facts can exist.
Memories are not facts. What people say are not facts. What people say others say are not facts. They all typically have some elements of fact.
Can't we all just get along?