He can use the falling injuries as an excuse. But I think he will try to get in the house before his mom notices he wasn't there in the first place.
Also, I'm really sorry for you guys having this kind of drama before the chapter came out. But this wasn't badly translated at all. I'm guessing it was mostly QC that was left and they felt some parts were a little sloppy. I'll read this chapter when you re-upload, I support you and thank you so much.