What mistakes does Squire Trelawney make?

Squire Trealwney is the figure in the book who finacially underwrites and initiates the treasure hunt. Although he appears to be on top of things, he often makes mistakes and his hiring of Long John Silver and the mutineers tops the list of misjudgments and miscalculations which lead to the downfall of the journey. He is very naïve and trusting, and, thus, is constantly being duped.