What according to gortsby was the weak point in the young man's storyhow was gortsby later convinced that he had made an error of judgement?

Gortsby identified the weak point in the young man's story as the lack of detail regarding a bar of soap he claimed to have lost, which seemed implausible. He later realized his error in judgment when he found a bar of soap in the park, confirming that the young man’s story was indeed true. This realization highlighted Gortsby's premature skepticism and the dangers of making assumptions without sufficient evidence. His initial confidence was undermined by the simple discovery, leading him to reflect on his hasty conclusions.