How does Napoleon's “cunning” plan with the timber go awry? What happens as a result?

Napoleon's plan goes awry when he sells a pile of timber to Frederick, who cheats the animals out of money. First, the timber is supposed to go to one farmer, and then the other. As a result, the animals can't get a good price for their timber. When napoleon finally thinks he has everything worked out.... it turns out the money is counterfeit.

What is the real explanation for Napoleons near death experience and the incident in the yard with squealer? Why do you think Orwell doesn't say it outright?

animal farm