* Missing articles: "Trial" should be preceded by an article like "at the" or "during the."
* Incorrect verb tense: "Lying" should be "of lying" or "of being a liar."
* Missing subject: The phrase "accused his lawyer" needs a subject. It should be "accused his lawyer of"
Here are some ways to restructure the sentence to make it grammatically correct:
Option 1: "One of the defendants at the trial jumped up and accused his lawyer of lying."
Option 2: "During the trial, one of the defendants jumped up and accused his lawyer of being a liar."
Option 3: "One of the defendants jumped up during the trial and accused his lawyer of lying."
These options clarify the structure and make the sentence grammatically sound.