Are there examples where a single person doing it gets successfully sued? It could just be that those companies were extra risk adverse so they came up with monetarily inefficient ways to defend themselves.
The courts said that was fine, and whenever that happens, lawyers are going to tell people to do it exactly like that since it's a known-good way to do it, whereas some other way is maybe and who wants a maybe if you have the option to lockstep the process that was previously approved?
Of course, if you do it a different way and then that gets approved, things change. But only after somebody actually goes to court over it, which generally nobody enjoys, not least because the outcome is uncertain.
It's sort of the other side of that coin. There was a case where a company did it like this:
https://en.wikipedia.org/wiki/Clean-room_design
The courts said that was fine, and whenever that happens, lawyers are going to tell people to do it exactly like that since it's a known-good way to do it, whereas some other way is maybe and who wants a maybe if you have the option to lockstep the process that was previously approved?
Of course, if you do it a different way and then that gets approved, things change. But only after somebody actually goes to court over it, which generally nobody enjoys, not least because the outcome is uncertain.