Suxamethonium IS a paralytic agent, but it has no anaesthetic or analgesic properties. The paralysis from 'sux' is so profound that respiratory muscles are paralysed - so anyone dosed is likely to die from asphyxiation. In addition, the half life of sux is pretty short - just a few minutes in normal subjects. So in summary, a character given the sux would be paralysed for a few minutes - completely aware of anything done to them, and possibly die from asphyxiation.
The goof item below may give away important plot points.
: Just before the crash, when Avery drives into the telegraph pole, Avery releases Jordana's seat-belt. When the scene is shown with Avery handcuffing Jordana to the steering wheel, Jordana is shown semi-conscious with a head injury. No airbags had deployed from the steering wheel or the passenger dashboard. The shot then pans round from behind with Avery leaving the car. The windscreen has no damage to it would be expected from a collision with a telegraph pole and a passenger that had no seat-belt on. There also appears to be what is left of a passenger airbag visible, but still no airbag from the steering wheel.