Looks like the loader only had the one place to put it and I'm guessing that nobody thought it was that heavy. I don't know what that loader can lift, but guess it has a 3 yard bucket on it, which should be in the 12 to 15,000 pound range. The log wasn't a challenge for it, but placing all the weight on the front of the trailer was.
In all honesty, I would probably done the same thing. The loader looked like he did a nice job of being gentle with it. If I wanted that log, I might be the one in that position. Hindsite is pretty easy when you see others mistakes, but I'm not experienced enough with big logs like that to know what they weigh or what the damage would have been.
Bending the frame on the truck just would never have entered my mind. I'm still amazed by it. The trailer, well that's fixable and sort of meant to be abused, so that's what I would have expected to be damaged.
Eddie