The reason Li Du wanted to scare Hans was that he didn't want any trouble caused in his hometown.
He understood very well the kind of a person Hans was. Hans was a playboy, faithless lover, genitalia in human form, self-propelled biological cannon, and male lead of a real-life pornographic film.
When they had first met each other, Hans was most adept at making booty calls and hiring prostitutes. He only began slowing down a little when the storage unit business picked up as he was busy finding customers and information on storage units.
Li Du did not want Hans to cause any trouble in his hometown. In due course, when the lady and her family were unable to find Hans, who had left far away to America, but was able to find out where he had stayed, there would be trouble.