Board Thread:Manga/@comment-30455198-20161202125754/@comment-27938131-20161207085558

Mule titan is indeed a shifter. Erwin did make that supposition and he was right. That titan is able to speak, and when he attacked Levi then Hanji it was clearly to save Zeke and Reiner from their imminent deaths.

For the female titan, Levi could have kill her. He just made Eren's rescue his priority, over her death. But I'm sure one of the numerous reasons she cried after was because she realised she could have die!