should you talk to your witnesses before court?

Mr. E, from Burundi, was denied asylum, even though he suffered great physical harm, and he had witnesses who came to court. Why did he lose his case?
1. On June 23, E testified he saw his brother at home. Brother testified that they saw each other, not at home, but at the hospital. The Judge said this means E is a liar.
2. E testified that he was beaten three times, and that he was in prison for one week. The letter from father said that E had indeed been beaten three times. However, the letter said nothing about being in prison. The Judge said this means E is a liar.
3. E testified he was arrested by government agents, who burned him on his hands. E produced hospital records showing that he was treated for burns on his hands. The Judge said, "OK, he was burned on his hands. But, who burned him on his hands? maybe his sister; maybe it was an accident. Also, why was he burned on his hands? because of his political opinion? Maybe it was for some other reason. I do not believe the government burned him, because of his political opinion."