You can get the "Die Hard" achievement after you finish the theatre level and without having made a single mistake in any of the levels. So to get the achievement, you have to not just not dying, you have to a perfect mistake-free run from the start game to it end.

I think, that this achievement just has wrong wording.
If you and your team-mate fullfing all the conditions to get this achievement, both players (as a librarian and researcher) will receive the achievement.