Isn't it pneumonia?

3 weeks ago I took my son to the emergency room because he was carrying a fever of 102 for 3 days and woke up with breathing difficulties. The doctor did a chest x-ray and said there was some cloudiness in his left lung but he said he only had acute bronchitis and sent us home with a antibiotic and cough suppressant.2 days latter I had to rush my son to another hospital ER because he was 10 times worse.He then was correctly diagnosed with strep pneumonia.Unfortunately it had gone to long and he had to undergo emergency surgery to remove all the gunk from his lung.He's been through and I am very angry because I was told by the infectious disease Dr. if he had a cloudy x-ray to begin with it meant he did indeed have pneumonia. Is she right or was the first ER doc right?