
Hajin is the only one that has truly seen things from Sihyeon's POV and it's honestly very wholesome of Hajin to actually empathize and become protective to Sihyeon. Yet, it was also good that Hajin also knows that the other member also wasn't evil and accepted their goodwill despite their past mistakes, only that he's hoping that it was Sihyeon that accepted their affection than him and that they did it sooner. But Hajin not blaming them much (I think) also means that he knows how difficult it is for them to deal with Sihyeon at that time.
This is so bittersweet I feel bad for Sihyeon, but I think he really deserve to finally rest... and have that fking btch manipulator ex-bf executed.