It's the boyfriend's house in that short clip, I went back and checked. We missed that the first time through also (thought it was the coughing neighbor).
It WAS the coughing neighbor attacking the birthday party neighbor. He had on the same plaid shirt. Maybe he was waiting for someone before they left? Or he got too sick to leave?
I find it hard to believe that the boyfriend didn't tell the daughter he was bitten by someone. That seems like a story most people would tell from the start. I mean how often are you bitten by another human being in your life?? Seems like everyone is avoiding telling the daughter what's going on. Not just the adults.
The coughing neighbor had no obvious injury. Maybe within a few episodes we'll know whether he bandaged up a bite and it was under his clothes, or if some people are just getting sick... I could see how that's possible also. Maybe the infection sickens and kills some people (people with poor immune systems for example) while others become carriers until death. Who knows??
Anyone else note that the mom and the teen left his supplies behind after fighting off the principal? You can tell it's still early in the infection. No way would TWD characters leave behind a cart full of supplies after fighting off a walker. lol. In fact, assuming the school is now "all clear" they would have cleaned the place out.
I completely understand why the mom didn't go help the neighbor. She just 'killed' her coworker/boss/friend. And at this point probably believes the infected are just sick/out of their minds, but "curable," so she feels like she killed him instead of saving him. I don't think she wanted to put her kids at risk by drawing attention to themselves and their home, but I also think she wasn't up to killing another friend/neighbor right after what she had to do at the school.
Surely after seeing the neighbor attacked, she'll finally realize she needs a weapon or two? I was surprised when she didn't start packing, planning, organizing when she got home. Weapons and Water (since their heading to the desert) would be my high priority at this point. I'd be thinking baseball bat, golf club, crowbar or something along those lines. So far, her family has had better luck with blunt force than knives and guns.