Do insurance companies in auto accidents go by the police report?

Answer 1

Sometimes they do and sometimes they don't.

Police officers who make out an accident report are rarely a witness to the actual accident and almost never investigate and auto accident unless foul play is suspected.

Typically an officer responding to the scene of an accident is simply noting observations and taking down the statements of others. There is no reason to assume that the officer knows all the facts, has interviewed all witnesses or even has the training to determine fault or legal liability. An insurance adjuster does have that training.

Although an insurer will certainly want to review any accident reports that have been filed to make sure they have as much information as possible, they do not make a determination based solely on a police officers accident report.