I think you confuse two things finding the data pads that will give a navpoint to the final location and finding the last data pad there.
There are no navpoints to the first three data pads you need to find (they spawn randomly same as other minor tasks) The final location however is not random but always in the same location. You may visit that location before getting the nav point to it. In that case nothing will be there. This is also true if you revisit the location after finishing Kadaras Ransom.
Actually It DOES concern Bodies. You have to "Scan The Bodies" at the final area to get the last Datapad. But Even though I have done it the quest has not completed.
September 2017 - last edited September 2017
For me, EVERY time you see the body and select the Pad, you then comment and the quest completes. That didn't for me now. so 9 out of 10