In "The Monkey's Paw," what happens immediately after Mr. White wishes for 200 pounds?

Immediately after Mr. White makes the wish for two hundred pounds, three things happen:

A fine crash from the piano greeted the words, interrupted by a shuddering cry from the old man. His wife and son ran toward him.

His skeptical and fun-loving son Herbert plays a loud chord on the piano, as if to create an effect of something like a magical feat being performed. His father drops the monkey's paw because, as he tells his wife and son, it seemed to twist in his hand like a snake as he made his wish. Throughout the story, it is never clear whether the wishes are being granted by the monkey's paw or they only appear to be granted as a result of coincidence. As far as the paw seeming to twist in Mr. White's hand is concerned, that may have been caused by his fright when Herbert startled him with the "fine crash" from the piano, which was more or less what Herbert intended.
After that, nothing happens. The three family members stay up a little while longer and then all go to bed. That is the end of Part I.
Mr. White is obviously a modest man. If he had wished for something grander, such as a mansion or a big bag full of gold coins, then the reader would feel sure the monkey's paw had supernatural powers. Mr. White only wishes for two hundred pounds, though. It could have been sheer coincidence that Herbert would get killed in a factory accident the next day and the company would decide to give Mr. and Mrs. White the sum of two hundred pounds as compensation for losing their son.