bizarre coincidence

My friend Robert has sent the following;

Son Theo is in India with a couple of friends. Last week, while I was in the
local library, my mobile phone rang. It was Theo reporting from Rajasthan.
I asked him to hang on for a few seconds while I went out of the library and
into the street; better reception and less disturbance to everyone in the library.
On the way out of the library I bumped into Sally (friend and fellow Bedales
parent). As I was telling Theo that I had just met Sally he excidedly announced
that Flora had just that moment got off the bus he was about to get on.
Flora is Sally's daughter ...

What are the odds? Its been driving me crackers thinking about it.
OK if the kids know each other and are perhaps at the same school, plus
similar folk hang out in the same places - local library- then its just 2 people
bumping into each other, plus another two, whilst being on the phone at the
same time.The distance thing is just a distraction. Can someone do the equation?
Please??