Well, it was 1967... Um...if the pod is still inside the ship, and you're just sticking out an extension, like a high tech butterfly net, wouldn't it make more sense to eject the extension rather than the whole pod? In other words, let go of the butterfly net rather than jump overboard? Only if Finney managed to shrink down to the size of Kenny Baker. There's a nice little comparison shot in the form of the closeup on that spot, courtesy of Denise Okuda making a cameo in the window just above. That burned spot isn't big enough to house anything big enough to constitute a manned sensor pod.