Board Thread:Anime/@comment-27321453-20181014183006/@comment-1327106-20181023071721

The boulder was very convenient for Trost. It happened to already be sitting in the city near the breach. They probably couldn't expect to be that lucky a second time. Big boulders don't grow on trees. :)

As for the citizens, my guess is that they just don't know Eren by name. Levi is famous and has a reputation. As far as Eren goes, the average citizen knows the Survey Corps has a Titan who plugged up the wall in Trost. Who that Titan is (or if it's even a person) is probably unknown to the general population.

There's a scene with Dimo Reeves that was cut from the anime, and it makes it pretty clear that he has no idea Eren can turn into a Titan. If he knew he probably wouldn't have tried to kidnap him.