is attack on titan (shingeki no kyojin) episode 12 filler?

The plan to lure Titans to the corner of Trost continues, even though the soldiers try to avoid combat as much as possible, a fifth of the men are lost. Commander Dot Pyxis, however, states that the soldiers do not die on their own as his orders are what send them to their death.

Saying that this is a critical point in mankind's survival, Pyxis declares that as long as humans manage to live on, he does not mind being called a murderer.