Everyone accepted reality differently and it was noticeably shocking for most students to be thrown into it without a warning.
Not only were they extremely weak compared to the Golden centipede King but also its subordinates were extremely powerful and strong enough to kill several students at once.
As such, Shane didn't think that it was necessary to hold a grudge against Mike, who had punched him, or Karl who wanted to blame him or even the dense Valkyries.
Rather than holding a grudge, which wouldn't help him in any way, Shane found that it was better for the three of them to reevaluate their attitude.
When Mike woke up with an aching body, he noticed that Shane was still doing well and looked seemingly unbothered while nobody else cared about his "fault", only for Karl to hold him back and explain everything to him.