"I am sorry for all the trouble you went through because of us, young man."
Jivem expressed his regret after Eren was done explaining to him all the hurdles he was forced to go through because of Ishgaar's Templars.
Of course, the reason Jivem was able to trust Eren's narration of the event right away was because he had done some investigation of his own during the last few days. He could confirm some of the things Eren had included in his narration.
Plus, Eren seemingly had no reason to lie to Jivem.
"And I am sorry for all the unjust deaths of Ishgaar's Templars as well," Eren responded in a regretful tone. "Those witches were really vicious. They had threatened to chop off my penis and offer it to some arch demon as a tribute. If it wasn't for Ishgaar's Templars, I really don't know what would have happened to me," he said with a fair bit of fear in his voice.