Geffe87

Chosen answer: He doesn't trust her. He knows Ethan is in love with Claire, and suspects she is in love with him. Claire does not deny this, and begs him not to kill Ethan, which confirms his suspicion.

Sierra1

Answer: Perhaps he planned to kill her all along. He was planning to escape via the helicopter but how was she to escape?

She was never supposed to go to the baggage area. She would have just got off the train like a normal person.