The doctor may be guilty of malpractice. The issue is, under the facts as that doctor saw them at that time--the symptoms your wife complained of; her medical history; the X-rays; any other tests or measurements--the doctor's diagnosis was reasonable (that is, a reasonable doctor could have thought pneumonia) and similarly, whether it was reasonable to "stop" there or whether a reasoonable doctor would have ordered additional or different tests or scans. The law accepts that good doctors sometimes are wrong even when they did everything right--when that happens, it is not malpractice. Malpractice is when a doctor's actions or diagnosis is not reasonable--basically sloppy, careless, uninformed (a doctor did not keep up with medicine or recommendations in this area), etc.Speak with a malpractice attorney NOW, before more time goes by--there is a relatively short time frame ("statute of limitations") for bringinging malpractice cases. The attorney can evaluate in detail the situation, advise you as to whether you have a case and, if you do, file it before much more time passes. Good luck.