The man who caught the boy was walking by with his wife and son, who spotted the boy falling.
Another witness told Le Figaro that the doctor positioned himself by the awning and caught the boy in his arms after he bounced off it.
The witness, Francois, said the boy cried a bit at first but quickly calmed down.
The doctor, identified as Philippe Benseniot by France Info, said it was pure luck.
"I was there at the right time," he told France Info.
The child was taken to a hospital but was found to be uninjured. Link -via Fortean Times
Correction 4 November 2010: Following French media, we initially reported that the baby was a girl, but have corrected the story to say he was a boy.
So I'll change this post as well.
One point does not a data set make.