Wait... What? PC rebooting shouldn't "clear" all of the data on it, only recent changes that weren't saved would be lost, so the old version of the file should still be available. Why did the FMC need a backup from home to access it? Wouldn't it be even older?
You were in charge... Of Igarashi-san's training, right? What'll you do?
How the fuck is Igarashi's inability to save her work FMC's fault? This isn't something you train your employees to do.
Of course this whole farce was only for the purpose of converting Igarashi to FMC's side, because this manga is the type to NEVER blame anyone, and ALWAYS have happy endings for everybody. Oh, you tried to frame me, use me, and kill my mother? Everything's fine! Everyone has a bad day sometimes!
If you want to write a story that redeems its villains, write it in a way that does so. Characters just always forgiving everyone and not holding grudges don't have any life to them, they feel like puppets in a play about forgiveness.
The last panel would be many times better than the actual story. Igarashi tried to push her work onto other people, frame her superior (TWICE), and never took any responsibility for her actions.
The author yet again proves that they should be forbidden from writing any drama.