Nobody is going to win in court with individual anecdotes about their keyboard failing. There also doesn't appear to be any proof in the Bardo anecdote that it's actually the butterfly design itself that caused the problem either. It could have been a manufacturing defect, for example. Apple has the numbers on the keyboard repair rate and what those repairs entailed, and it seems unlikely that the majority would be an actual failure that requires the keyboard to be replaced.
Anecdotal stories are just the starting point. The trial itself is an investigation of sorts. Apple has the keyboard repair rate data, so if Apple wants to show the keyboard failure rate is normal, then they'll be expected to show it. If they refuse to show it, that looks really bad.
In any case, we aren't limited to anecdotal stories. Some limited data about the keyboard repair rates has leaked out. Although it is incomplete and it can be interpreted in a couple of completely different ways, the simplest and most likely explanation for how bad the data looks is that the keyboard is significantly more unreliable than other Apple keyboard designs.