First, David did an excellent job. Major kudos to him for fast thinking and cool operation. Yes his hand got burned, but he didn't even realize the lever was hot until after he got out of the airplane.
Second, moving forward and thinking about the scenario in terms of "what would I do" I think Henning makes a good point. Were my cockpit filling with smoke, the only thing the airplane is good for is getting me to the ground without injury. That's it. The minute something goes wrong the airplane belongs to the insurance company, and I will do whatever I must to ensure a safe landing. My insurance company would like that as well, as they'd rather buy me another airplane than pay my widow for my crispy crittered corpse.
If the gear doesn't come down, and lowering it delays my landing by ever a couple seconds, screw the airplane. They can fix it. They can't fix a crispy crittered me. The most I'll ever pay for a wreck is my insurance deductible. The worst I could be hurt is way worse than that.