There's a big difference between "should be fine" and "will be fine". When the stakes are small, the former can be enough. But as the stakes get larger, people favor the latter.

At a large company, the stakes get large in two ways. One is that all the numbers are just larger. But more important is that an individual decision maker's career success can become dependent on a relatively small number of things. E.g., if a lawyer approves a license that should be fine but actually isn't, that could substantially harm career prospects. It still may be a small problem overall for a major company, but if it means somebody gets fired, those are pretty big stakes.