> How would the plaintiff know the exact method used?

This is not exactly difficult. They are alleging that this was installed on a million phones, I'm sure doing some straightforward technical forensics would make it clearly apparent what was going on.

> Why would the fillings _not_ be biased to the side being represented?

You've misunderstood my point, though I don't understand yours. Of course the filings are biased, that is exactly what I'm saying. I've just seen numerous cases (myself included) where people get out their pitchforks when they've only read one side's version of events, well before a complete picture emerges of what actually happened.