In the video of Riley Cuskey's death there is not nearly enough blood spilled to cause a healthy person to die. If the femoral artery is severed blood flows out as if from a hose. Death is very quick, a few minutes at most.
Olivia asks Cassandra what exsanguinate means ("bleed to death.") In Serendipity (2003), three seasons earlier, Dr. Melinda Warner used the same term, and Olivia gave the definition. However, it's likely that Olivia was trying to build rapport with Cassandra.
Cassandra's doctor incorrectly states that wisdom teeth do not erupt "until you reach adulthood". While it is true that in most cases wisdom teeth only erupt after age 17, they can erupt much earlier.