Marine Punished to death in Iraq?

I used to be in the Corps, and saw a number of marines collapse due to heat exhaustion. Two of these were during "PT" exercises, when the Marine was being punished. (once in boot camp, once in the fleet) So I know the following article is possible. I just wanted to know what others thought on this issue. Bear in mind, this kind of punishment is done to avoid administrative punishment against service members. It is also done to "harden them up". Thoughts?

LAKE STEVENS, Wash. (AP) -- On the afternoon of March 23, two superiors took a 21-year-old Marine, Lance Cpl. Dustin Canham, into a tent at Camp Lemonier, a U.S. base in the rocky desert of the Horn of Africa.

Exactly what happened inside remains unclear, except this: Canham died.
In letters, the Marines told Canham's family he collapsed while exercising. His father and his 19-year-old widow believe that's half the story. They were told by Canham's fellow Marines that he was being punished for accidentally chipping another Marine's tooth. They suspect he might have dropped dead from being forced to work out too hard.
A military autopsy determined the manner of death to be "natural" and said Canham had a mildly enlarged heart. But the medical examiners were not told the circumstances of Canham's death and thus did not consider heat exhaustion as a possible cause, The Associated Press has learned.
After the AP raised questions last week, Armed Forces Medical Examiner Craig T. Mallak and the deputy medical examiner who performed the autopsy, Cmdr. Timothy D. Monaghan, told the family they would take another look at Canham's case.
"They try to make it sound routine, but there's nothing routine about taking one Marine aside," said Canham's widow, Devyn. "Why wouldn't they be doing their daily exercises together?"

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