Why was Ji Xiaolan exiled?

In A.D. 1768, Ji Xiaolan, favored by Emperor Qianlong, was found guilty and exiled to Urumqi because he tipped off his in-laws Lu Jianzeng. Just as Ji Xiaolan had a smooth sailing in the officialdom and was promoted step by step, a bad luck in officialdom quietly came to him. In this year, Huai Salt Transportation Company lost100000 taels of silver, and Emperor Qianlong wanted to investigate all previous Huai Salt Transportation Ambassadors. Lu Jianzeng, one of the ambassadors of Huai Salt Transportation who had returned to China at that time (Ji Xiaolan had previously married his eldest daughter to Lu Jianzeng's son) was also under investigation. Because of in-laws, Ji Xiaolan had privately disclosed this matter to Lu Jianzeng, which made Lu Jianzeng transfer his wealth as soon as possible. Ji Xiaolan's way of letting the cat out of the bag is also interesting. It is said that when Emperor Qianlong later traced the leak, Ji Xiaolan insisted that he had never written a word. Even Emperor Qianlong was curious and didn't understand how Ji Xiaolan let the cat out of the bag. According to The Complete Biography of Ji Xiaolan in the Song Dynasty, "After careful consideration, he finally came up with a wonderful method: he took a pinch of salt and a pinch of tea, put them in an empty envelope, sealed them with paste, and sent them to Lu Jianzeng's home overnight without writing a word inside and outside. After receiving the envelope, I was surprised at first and poured the contents on several boxes. He read it, speculated for a long time, and finally understood the intention:' The salt case was found to be empty (tea)!' As a result, the borrowed public funds were quickly filled and the remaining assets were settled elsewhere. Everything is ready, and the raiders are late. It's been half a month. "Some scholars say that the above list is not true. The fact is, Ji Xiaolan told Lu Jianzeng's son, Lu Qian, face to face when he heard that Ganlong wanted to track down the salt case deficit. So Lu Qian wrote to tell his father Lu Jianzeng. In fact, when Qianlong traced the deficit in the salt case, Lu Jian had already left his job and retired to other places. However, although Ji Xiaolan's leaking way in the above biography of Ji Xiaolan is worthy of scrutiny, it is Ji Xiaolan who leaked the news after all. Moreover, it is also true that Lu Jian once bribed salt merchants with 16000 taels of silver when he was a salt carrier in Huaibei. Later, Ji Xiaolan's secret was discovered. At the same time, it was found that more than one person leaked secrets to Lu Jianzeng, as well as Xu Buyun, the alternate book of the military department, Wang et al. 100, and later they were all involved in the case. In the end, except for more than 20 people who were killed, all the others who were involved also ended up in exile in the frontier and served as atonement.