Wait, let's back up to 'human remains' for a minute.

"That's not what they are!"

This: shouted after Bhamba in a tone reminiscent of 'oh god why would you say that how dare you say that you asshole oh god why would you say that'. Then Alex pulls himself together by force, and stands there shakily. Giving in to sudden anger - that's what a splicer does. He isn't a splicer. He's human and he's sane.

He puts a hand to his face. It's not tumorous or falling in on itself. He came back human and sane, didn't he?