At the 11:20 mark, Toby and Will are in the truck. Toby can be seen lighting a cigarette and taking a drag with his right hand. When the camera cuts, Toby has the cigarette in his left hand.
Will rules out the possibility of the image retrieved from a corpse being a memory of the deceased person, on the grounds that it does not match the events that took place in real life. Science has discovered, however, that memory is in fact not an accurate record of what one perceives but rather a distorted and malleable one, and Will, being a neurologist, must have been aware of this.
When Will saves Isla, she tells him: "You were supposed to be the last person I ever spoke to.".
But after they talked while she was hitchhiking, she got a ride, so the last person Isla talked to should be the driver, at least to tell him where she was going to (even is she might be meaning that Will was "the last person she had a significant conversation with").