Back then, when Shi Tian was still wavering on the decision whether to send Vanessa away or not, he had accidentally overheard her conversation with a mysterious man on the phone.
As he was listening to the conversation, he realized Vanessa already had her people arrive in Gearits City but merely concealed themselves.
Thus, it became clear that Vanessa was now protected and he didn't have to be worried even if an incident like the assassination from Kralos Tal happened again.
With how mysterious Vanessa's identity was, he was positive that Kralos Tal wouldn't pose a problem to her given that her people were here.
That was the elaborate explanation Shi Tian had but kept to himself. After all, his explanation at the end of the day still remained that he was gambling on her safety.
If it was the other way around, Shi Tian himself wouldn't have forgiven the other party as well, at least not easily.