Neil Armstrong and the missing "a".

As we come up to the 40th anniversary of the moon landings, I've just been watching a program about the Apollo program. In a rather rare interview with Neil Armstrong I noticed something interesting.

Transcribing part of the interview, I get this:

    The descent was very tricky business.

    The challenge was to try to land at a relatively
    specific landing site that had no runway, no control
    tower, no radar, and no navigation aids.

    Our plan was to start at a specific point in lunar
    orbit at about 50,000 feet altitude, and something
    over 3000 miles per hour, to use one continuous
    rocket burn to decelerate to a hover in the landing
    area.

The first "a" before "relative" is extremely short, and there is no "a" at all in the first sentence. It's true that the first sentence above does parse without the "a", but it also parses with one.

Armstrong has said that he intended to have an "a" in that sentence, that he rehearsed it, and that he thought he said it. He has also had the recording played to him many times, and has finally admitted that it's not there, and he's surprised.

My theory is that it's a dialectic elision. His brain said it, but his speech path never passed it on to the rest of us.