Having read about historical radio astronomy and practiced signals analysis, I think they were a little more sophisticated than that. The recording in this format was made for easy perusal by a human, say, the next morning. I think that was the case with this signal. No doubt they wanted to revisit that spot in the sky looking at intensity, frequency shifting (Doppler), bandwidth, modulation, etc. But they never saw it again.

Historical point of interest: the Big Ear telescope that recorded this was bulldozed to make way for a golf course.