I agree. Much like the dreggs on the pikes at the beginning of the mission, the body would disappear once the mission was completed. Bungie did that for various things in other missions, so it would be no problem for them to create a grave after mission completion. Hell, look at the shrine they made for the loot cave. Thousands of hive get a speaking shrine and yet one lone, unnamed guardian gets his body left for all to walk on? Not right at all.