Abby's death was, without a doubt, tragic. Even Joe, who didn't know her as well as others, felt the sadness weigh on him. She was a nice girl, and they had talked on several occasions. But it didn't hit him as hard as Jay's death did. Maybe it was because he still wasn't over Jay's loss, and that made it hard for him to grieve for Abby fully.
More than anything, though, Joe was worried about Max. He couldn't help but feel for his friend, especially considering how much this was affecting the people still around him. Joe wondered if part of the reason he felt so anxious was because he relied on Max in more ways than one, not just financially, but as a source of guidance. If Max was struggling, then Joe knew that it would affect him, too.
Or maybe... maybe it was just because he felt bad for Max. He could see his friend breaking, and Joe just wanted to do something, anything, to help him feel better.