The American English dubbing is inconsistent.
Clare actually does have access to her mobile phone after Andi removes her SIM card because it is possible to make an emergency call without one.
It is improbable for Andi to liberate his impaled hand from a screwdriver without any sharp edge the way he did.
Clare had many opportunities to bash Andi's head with a frying pan, textbook, or other heavy object while his back was turned.