[fumbly]

> No, all the choices have already been made. The data have already been destroyed

You don't know that. You'd need an investigation to conclude that. Using it as an excuse not to investigate seems like assuming the conclusion.

Even if some data have been destroyed, it doesn't follow that every last piece of data everywhere has. Who knows what might turn out to be significant? There may well be relevant data in many countries, too, since the research was international.