First, I was under the impression that an Avel is not supposed to greet people, so your halacha seems to be contradictory.
But for argument’s sake, let’s say I agree with you – in that case, when I started a conversation with him, why did he run away? Also, I want to know the story. I was also mid-conversation when he interrupted – so why do this.
Clearly, this person has a back story behind it. Are you trying to tell me that he feels to many people are flouting halacha when making a shiva visit?