I don't want to distress you, but there is NO way to know for sure. It all boils down to how honest the poeple were that handled the cremation.
Several years ago there was a huge nightmare in a neighboring city because a funeral home operator failed to creamate bodies (human). When the police finally investigated they found decaying bodies all over several acres. What the scumbag told the authorities was that his crematorium was broken. The "ashes" that a couple hundred families has received was concrete.
The man is in jail and the funeral home has since been closed. Here is a link to the story:
Tri-State Crematory - Wikipedia, the free encyclopedia