Spoiler from DarkUFO's source Post Produxtion:
Ben admits that Juliet was chosen to be his, as in a mate. Not to be with Goodwin. And that he wouldn't let Goodwin leave the tailies group specifically because he wanted him to get killed. This all becomes clear to Juliet as Ben shows her Goodwin's dead body.
Source: Post Produxtion@DarkUFO