Board Thread:Questions and Answers/@comment-30771283-20180412120625/@comment-5774380-20180412134504

It's not necessary to eat the whole body of the holder to inherit the Titan powers, only the spinal fluid; and that's what we [and Eren] assume he drank along with the rest of her fluids when he squeezed her like an orange.

Also, when they fled, Eren was only focused on Reiner and didn't seem to mind much about leaving Galliard behind; contrary to what it would be expected if he had failed his mission and was leaving the War Hammer with him as well.

There might still be a small chance that Galliard inherited the powers instead (and it would be an interesting plot twist); but it seem this option hasn't been considered to be probable enough to raise doubt. 🤔