Now why on earth would he do that? Just as Heiji had pointed out, it has absolutely nothing to do with him. He just happened to be the unlucky person grabbed in her stead, that's all.

...And yet, he feels chilled by the very idea. He knows there isn't any expectation - couldn't be, really - that he would have been any sort of actual replacement for that girl. But nevertheless, a life was lost, and he was the one Calhoun had dragged in to take her place even as the others were still mourning.

The others had been uneasy when they first spoke with him. It's only too clear why.

After a short moment of silence, he finally speaks again, his voice even quieter than the norm. "...Sorry."

Whether it's for their loss, or being forced to act as a weak stand-in, not even he's certain.