So far, I've only read the abstract, but I see two problems with this approach.
One is that they are looking specifically at open source projects, which, as other comments have pointed out, can technically meet their definition of a "hero project" without anyone engaging in the types of heroics normally associated with that term.
The other problem is that they talk about comparing hero developers to non-hero developers, when they should be comparing hero projects to non-hero projects.
If hero projects (as the paper defines them) are so common, then the pool of non-hero developers is going to include a lot of non-hero developers working on hero projects. Of course those people make more mistakes than the heroes, they're less familiar with the project. But those mistakes were made following the hero project model and should count against it, not for it.
One is that they are looking specifically at open source projects, which, as other comments have pointed out, can technically meet their definition of a "hero project" without anyone engaging in the types of heroics normally associated with that term.
The other problem is that they talk about comparing hero developers to non-hero developers, when they should be comparing hero projects to non-hero projects.
If hero projects (as the paper defines them) are so common, then the pool of non-hero developers is going to include a lot of non-hero developers working on hero projects. Of course those people make more mistakes than the heroes, they're less familiar with the project. But those mistakes were made following the hero project model and should count against it, not for it.