User blog comment:Garhdo/Plot hole?/@comment-1221773-20111225154639/@comment-1221773-20111225222944

Again, it was probably too much trouble. The Collectors would have to land the ship on the planet, send a team out to retrieve the remains, and leave the area before anyone responded to the Normandy's distress beacon so as to keep their involvement hidden. It would have been much less risky to wait a bit and have the body brought to them by an intermediary like the Shadow Broker.