Visible crew/equipment: Before Lorna has her throat slashed, you can see a tube pumping the blood.
Continuity mistake: When Miroslav is massaging Whitney in the hot springs, the amount of body scrub cream on them drastically changes during shots.
Continuity mistake: After all the rich people bid on the girls, they cut to an American talking on the phone to someone. A school bus pulls up outside and his kids get up from the table with their school things and head for the bus. A few moments later the bus pulls away, yet you never see the kids get on the bus. The door to the bus is in plain sight at all times and when the bus pulls away you see no other door that they could have used.
Continuity mistake: When the woman is covered in Lorna's blood, the thickness (amount) of blood on her face changes from shot to shot.
Continuity mistake: When Beth is first captured, the gun held by the business man is a single-stack .45 ACP 1911 pistol (evidenced by the magazine at the bottom of the weapon). A few seconds later, when the children are lined up, the gun becomes a Beretta with a standard barrel. A few seconds later, when the silencer is attached, the gun magically has an extended threaded barrel (to allow attachment of the silencer). The silencer that was used obviously screwed on, which would not attach to a standard factory barrel.
Continuity mistake: During the "Bathroy" homage bloodbath scene, Lorna's back is to Ms. Bathory while she slashes Lorna with the scythe. Lorna's face is then to Ms. Bathory after she picks up the smaller scythe so she can slit Lorna's throat.
Revealing mistake: During the bidding, the girls' pictures on the phone are obviously super imposed images and not really the picture phone screens.
Visible crew/equipment: When the rich guy couldn't go through with killing the girl with the chainsaw, after the dogs had basically eaten most of him you can see the green screen in the elevator.
Other mistake: Lorna is hanging too high for Ms. Bathory to slit her throat with the small scythe while lying down in the tub during the bloodbath scene.
Revealing mistake: When the cannibal torturer is cutting into the leg of the victim, you can see its fake legs made of rubber or other material.
Continuity mistake: When Whitney is talking to Beth after Beth has just got off the phone to her dad just before they leave for Prague, you can see the bags that Whitney is holding keep moving. In one shot, both her handbag and holdall are being held in the middle arm area, but in the next shot, her handbag is around her shoulder and the holdall in her hand.
Answer: The kids were beating on Beth. If she was beaten and bruised she's worth less money. So Sasha told the "leader" of the gang to choose one to die or he will.