It was not coincidence. Neither was it a random estimation. It was rather the magic of our subconscious mind. As I have already told you that our subconscious mind knows past, present and future. We can estimate so many things correctly if we understand the power of subconscious mind. And it is more accurate if there is practice of using it collectively like mentioned in the above case.
The famous saying ''Unity is strength'' works in Psychology too. You know that subconscious mind has amazing powers. If many subconscious minds work together for the same purpose, they bring miracles. I think this concept is developed first time in the field of subconscious mind. There is need of more researches in this concern.
Discovered by Don Prince