Continuity mistake: Marta goes to Ransom to tell him about the blackmail letter. During the scene, the position of Chris Evans' hands is inconsistent between shots (he suddenly has his hand under his chin in just a close-up, and he is holding the letter at a different angle when he tells Marta that the toxicity report will shot the overdose). (01:28:50)
Continuity mistake: At the end of the car chase, Marta is looking at Blanc shielding her eyes with her hand. When he says "I don't know what he came back to do" etc, Marta's hand is off her forehead, but is on in the shots before and after. (01:34:05)
Continuity mistake: When Ransom asks "Fran's alive?" to Blanc, Chris Evans has his hand raised, thumb before his lips. But the hand is lowered in the shots before and after. Similar situation when the word "Jail" is used a few seconds later. Hand visible in close-up, not matching the wider angles. (01:58:10)
Continuity mistake: At the beginning of the movie, Marta is sitting at the kitchen table with her mom while her sister watches crime drama. The arm position of her mom keeps changing during the scene. When she says "Turn it off NOW" she has her elbow on the table leaning on, and then lowers it, still keeping it on the table. In the shots before and after both her arms are off the table. (00:03:00)
Continuity mistake: When the detective (Benoit) asks Marta to be her "Watson", the wind is blowing hard enough to move their hair. In the reverse shot, it is calm.
Continuity mistake: Marta picks up the phone at the beginning of the movie. In close-up she is holding it with her left hand, but at the cut it switches to her right hand. (00:03:20)
Continuity mistake: When Ana runs out of the gates in the back yard they're left open, but when Ransom returns at 3 am they're closed. And even though it hasn't rained for a week it is still muddy.
Answer: To add slightly to the other answer, evidently some of the blood in the scene had to be digitally removed for the film to secure a PG-13 rating, which explains why we don't see any actual spray/gush. But we are to assume that a drop managed to splash onto her shoe when he slit his throat.
TedStixon