Military returning wrong/unidentified remains?

Summary: Marine 1LT Dustin Shumney was killed in a chopper crash in Iraq, cremated, and his ashes were given to his widow. The volume of ashes was normal. Four months later, the military located and identified another 80 pounds of remains (also DNA matched to him). The additional remains were cremated and also given to his widow. Problem: The total volume of ashes was more than double the normal amount. The military blames it on embalming powder and bone density.

This strikes me as quite strange. Is this just a normal variation in weight and volume of remains, as the military is saying? Were there additional KIA's that were not identified? Why did it take 4 months to link the additional 80 pounds of remains to him? (Every servicemember deploying now has a DNA sample in the repository for just this possibility.)

To add insult to injury, someone stole the USMC flag from where it was flying in front of Mrs. Shumney's house last month.
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Excerpts from the article:

"Widow suspects remains more than husband's alone: Volume of ashes raises suspicion, but military says all crash victims ID'd"

Julie Shumney has dedicated an alcove in her Mesquite home to her husband's memory. There, she keeps photos of Marine 1st Lt. Dustin Shumney and the Fallen Friend Medallion presented after his death in a fiery helicopter crash Jan. 26 in Iraq.

The shrine is also the resting place for the ashes from his cremation in February. So the 32-year-old widow was stunned last month when the military called to say it had another large portion of her husband's body.
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Mrs. Shumney said a Marine Casualty Assistance Calls officer had told her earlier that if any other remains were found, "it would be something really minute."

But the ashes from the second cremation filled an urn by themselves, she said. And Mrs. Shumney learned last week that the two sets of ashes combined wouldn't fit in a 400-cubic-inch double urn, designed to hold the remains of two people.

All this has her thinking the unthinkable – that she could have the remains of another soldier as well as her husband.

"They swear that only Dustin's DNA is coming up in these remains, and there's no way," she said. "If I have another Marine's remains, I feel very honored to have them, but at the same time, I feel that their family should have them, not me."
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A spokeswoman for the Armed Forces Institute of Pathology said remains from all 31 personnel killed in the crash had been identified and sent to their families. And a spokeswoman at Dover Air Force Base in Delaware said that only Lt. Shumney's remains were sent to his wife. "All of our nation's fallen heroes' remains or partial remains are positively identified and confirmed either by fingerprints, dental records or DNA testing conducted by Office of the Armed Forces Medical Examiners," Air Force 2nd Lt. Chris Sukach said in a written statement.

"His remains were covered in his dress blues, and underneath he was completely wrapped in some type of cloth," Mr. Crouch said. "You could not tell how much of him was in the casket" because only the top portion was opened for the viewing. Mr. Crouch said he was shocked to learn later of the additional 80 pounds of remains. "It now looks like there was nothing there in the bottom half" of the casket, he said.
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www.dallasnews.com... (Subscription only, and not re-posted yet on a free site. If you all want, I can post the full article.)

It, common knowledge that the ashes you get when a loved one is cremated are only really a representation of them. "All" the remains may not be there, and quite possibly there could be other sorts of materials in there making up those ashes.

This doesn’t strike me as being overly odd.