Why isn't trelawney able to hit the gunner Treasure island?

In Robert Louis Stevenson's "Treasure Island," Trelawney is unable to hit the gunner because he lacks experience and skill with firearms. His inexperience is highlighted during moments of tension, where his hesitation and poor aim become evident. Additionally, the chaotic environment and the stress of the situation further hinder his ability to act effectively. Ultimately, this showcases the challenges faced by characters in high-stakes situations.