Hao Jian had been watching and listening from the side. The reason he didn't step in when Lin Dongyang was being attacked by a group was that he wanted Lin Dongyang to handle some things on his own, to face some situations alone. After all, Hao Jian would eventually leave and couldn't be by his side all the time.
Moreover, he wanted to develop his skills and then help Liang Xiaohan by resolving troubles for her. So, not everything could be solved by Hao Jian; Lin Dongyang had to rely on himself. Even when just now Lin Dongyang was attacked by five or six people at once, Hao Jian still stood aside and watched silently.
A person must go through certain things to grow, and this was true for Lin Dongyang as well as for anyone else. Therefore, this was a small matter, and it wouldn't be good for Hao Jian to interfere too much, as it might be detrimental to Lin Dongyang.
