Even if the barge did cause the break, it could still have been an act of God that broke the barge from it's moorings and flung it into the levee. Only thing that surprises me is that a barge could get enough sideways (relative to the length of the canal) momentum , even pushed by the storm surge and winds, to do that kind of damage to the concrete levee. (or more properly the concrete top to an otherwise earthen fill levee, as you can see fairly well in both pictures in post 15. I've seen other pictures taken from the levee itself, of the barge and the concrete top barrier. The earthen fill forms most of the levee and the canal itself which is elevated above the level of the surrounding terrain, with the concrete slabs just forming th e last several feet of the barrier.
The barge does not need to punch through the levee, just crack the cement and the water working on the earthen fill will do the rest.
Doesn't it look like the water is flowing into the levee in the bottom two pictures?
The barge slipping it mooring is an act of God only if He is the one who tied it up.