https://www.nlm.nih.gov/medlineplus/ency/article/000087.htm

FWIW. I think that patient might have sustained a pulmonary contusion or contused lung due to his accident.

Pulmonary contusion is trauma-induced lung hemorrhage and edema without laceration.

Pulmonary contusion is a common and potentially lethal chest injury that results from significant blunt or penetrating chest trauma. Patients may have associated rib fracture, pneumothorax, or other chest injuries. Larger contusions can impair oxygenation. Late complications include pneumonia and sometimes acute respiratory distress syndrome (ARDS).
Symptoms include pain (mainly due to injury to the overlying chest wall) and sometimes dyspnea. The chest wall is tender; other physical findings are those of any associated injuries.
http://www.merckmanuals.com/professional/injuries;-poisoning...

What is a pulmonary contusion?
A pulmonary contusion is bruising or bleeding of your lung tissue that may cause pain and trouble breathing. It is a common lung injury after a blunt trauma to the chest. The force of the trauma may cause bleeding and swelling inside one or both of your lungs.
What are the signs and symptoms of a pulmonary contusion?

You may have more than one of the following:

Chest pain

Trouble breathing

Coughing up blood or large amounts of watery sputum (spit)

Fast and shallow breathing

High-pitched wheezing when you breathe out
http://www.drugs.com/cg/pulmonary-contusion.html

Blunt chest trauma can cause severe acute pulmonary dysfunction due to hemo/pneumothorax, rib fractures and lung contusion.
http://www.ncbi.nlm.nih.gov/pubmed/20108554