Deanna there are so many people past, pregsent and future who have been and will be wrongly convicted. DNA or no DNA.
You may know that this particular Prosecutor's Office crime lab has been under investigation for tampering with evidence including DNA evidence. (Yes, they have their OWN lab not an independent one!)
You hate to think about them planting evidence but, it happens.
It depends on the oversight, how thorough the labs are about procedures,
and their integrity or lack thereof at 'winning' at all costs.
Once they take samples and they are in their custody, who knows where they might end up.
I am glad your co-worker's son was able to clear his name.
But, you can't say justice was served ever.
If it were, this innocent man would never have seen the inside of a prison cell and spent one minute of his life wrongly convicted. It will affect him in ways that can not be undone.