Its not missplace because it didnt happen in chapter 10. They re-did the scene to avoid repition and added Mah's part of the day. Atleast thata my understanding.
Also Mah's haircut isnt the one from his young self, its the haircut from his curremt self.
The guy could have just out his piercings back, and i cant tell for sure if he has his young or current self haircut but i think its the current self one
Ooooh actually you might be right.
It says "Bonus Track" in the up left corner AFTER the panels of the MC opeening the door for his mom. So i guess that was a page from.the previous chapter. And the haircuts makes sense if that happened right before the 1st chapter xD
(┛◉Д◉)┛彡┻━┻
Sorry guys it's most likely a missplace page

Eeeeh wtf so Mah actually left the MC??? And only came back because the other guy was still focused on crimee??? Wtf thas was horrible. Mah had already did his goodbyes with the guy and he is back to him right after.