Brand New Flat-Bedder Here!

I'll add do a final walk around and inspect your hook points, on both sides of the trailer. What I do is try and throw the straps from the passenger side. Then hook them all, then go to drivers side and tighten. I usually roll up the straps starting from the back of the trailer to the front and set them in the winches, grab my winch bar from the truck and tighten from front to back.
Same principle with chains. Throw them over, hook the RH side, binders on the LH side.
However, some times the chain gets unhooked, or caught, or twisted, or who knows what. Just because it is tight on the LH side, doesn't mean it is tight on the RH side. I've had it happen rarely, but just often enough that it pays to do a final walk around everything, and look at both sides to make sure its good to go.

 

We like pictures.

 

Well in addition to splitting the securement with chains, he had multiple layers and only a few gut wraps. I didn't see one belly wrap on the entire load.
Not only is it a DOT requirement on all multi layered steel, but common sense would dictate, that if you have to hit your brakes, you would want that belly wrap.
It tightens as the load began to move and can stop it from joining you in the sleeper.