Yes propaganda and bullshit, but by way of exaggeration and puffery, not lying.
I wouldn't expect even a lightly informed mid-wit to think that this murderbot held the ground by itself; and I don't think the author expects that either. Thus something else is probably going on. To wit - puffery.
The murderbot is remotely operated, so it did not held the ground by itself, though it is claimed that it might be able to do some things autonomously.