Just a few observations. The chain appears very loose. He should tighten it first. The carburetor should be set back a bit; the chain's still racing around the bar when on idle. Scampering over a log while holding a chainsaw with the chain moving is not prudent. He's getting some kickbacks, probably from pinching, and doesn't seem to notice. Little ones can lead to a big one. It's like a horse getting light up front as a prelude to rearing. Gotta pay attention to the small signs. And finally, I didn't see him engage the brake before struggling with that drop start.