is attack on titan (shingeki no kyojin) episode 28 filler?

In the ruins of Ragako, Conny stands by his house where the small-limbed Titan lies. Reiner and Bertholdt join him, asking if any survivors were found, and Conny tearfully informs them that no one was found.

Reiner comes to his side to comfort him while Bertholdt stands aside. Gelgar joins them and asks if any bodies were seen, and the three recruits admit to seeing none.

Gelgar wonders at this while Lynne proposes the idea that they escaped to Wall Sina before the Titans arrived.