Right when the ROV operator is saying, "The magnemometer is picking up a lot of anomolies out here'" the ROV light sweeps directly onto an open piece of luggage. The ROV camera stays focused on this for a few moments, and then the camera picks up a number of other obviously man-made objects clustered together on the ocean floor. If your job was closely scanning these images, wouldn't you say, "Look - theres lotsa stuff down here?"

This is why Sam Thomas wasn't used for the part - he was too smart to have missed this. . .