2x questions:
- What did the piece of hair at the end represent? It is not related to DNA purposes because Jerome had left enough genetic material for a lifetime.
- Who really killed the mission director? I thought the Director Josef's reason for doing it was weak and unconvincing.
Spoilers below.
Jerome (Jude Law's character) gives Vincent (Ethan Hawke's character) an envelope when they last see each other. He tells Vincent not to open it until he's "upstairs". As Vincent is finally travelling into space, he opens it and finds a lock of hair. I think this is Jerome's way of travelling with Vincent, fulfilling his dream.
The Director killed the mission director. Perhaps the mission director and the Director hated each other the whole time and the mission director was trying to abort the mission solely because he knew the Director wanted it one more time. You're right that the movie didn't think it important to emphasize motivation. We only know that the Director hated him enough to kill him and spit in his eye but we never saw the reason for the hate.
Well yes it was stated several times that the mission director was trying to have the mission aborted. The Director was hell-bent on seeing it happen. That's it.
shareI thought that perhaps the director admitted to it with that motive because he knew that Vincent was an imposter and wanted to see him go up into space. They made eye contact at one point when the director offered to take Vincent's trash for him, so I suspected he knew it was him, and wanted him to achieve more, like he always dreamed.
shareMy girlfriend is convinced Vincent killed the mission director. Look at the facial expression on the Director in the interrogation room. And the glance he gives Vincent. And how easy it was to spit onto the corpse.
Vincent lost his temper outside the restaurant and pummelled the police officer. He had the power and the temperament. She's convinced me.....