Wrong body in coffin? Does it matter?

Feb 9 2013 I read in the Daily Mail that a funeral home delivered the wrong body to a crematorium in Gateshead.
I avidly read the readers' comments.
I agree it's better to have the lid off the coffin so you know who is in there. If nothing else, it saves that uneasy feeling that maybe the person is actually alive. Stops wishful thinking of widows who are in denial.
You might need to exhume a body over a claim that somebody was murdered, whether the case is brought by family or police or insurance company. You might want evidence of cause of death for medical research. Or DNA to prove claims by descendants for inheritance from the will. If you are not looking after your relatives from cradle to grave, you might as well say goodbye to everybody whilst they are alive, and get rid of cemeteries and put everybody down the rubbish chute. Mourners want to cling on until the last moment, keep something. It's shutting the door after the horse has bolted, but for many its instinctive to try to hold on to the body or help the dead person and preserver their memory.
As for donating to medical research instead of cremation, unfortunately many old people die of cancer or infections and the bodies are not suitable for transplants and not wanted for research.