Factual error: The Daily Astorian office where Rachel works has the Columbia River in the background, however the real Daily Astorian office is located well off the waterfront. (00:10:15)
Factual error: There are several problems in the hospital scene where the psychiatrist commits suicide by giving herself an air embolism (injecting air into a vein): the volume of air she injected wasn't large enough to cause death (it appears she used about 30Ml, over 100Ml would be needed), death wouldn't be as quick as was portrayed, and it wouldn't be nearly as "peaceful".
Answer: The deer were attacking the car because Aiden was in the car. Aiden was possed by Samara at the time and Samara makes animals go crazy.