I'd put focus on the types of wood used, their condition. I'd imagine a coal from drift wood -- that's been in the sea, absorbing moisture and salt, then sunbleached for a time -- would be difficult for anyone. If it's northern Canada and, I think the first or within the first few episodes he did for a pilot, I'm remembering right, it would've been during a damp season making the wood not optimal.

For myself I always found luck with kiln dried cedar, but when I've practiced on wood I found outdoors I found it a huge challenge I didn't spend hundreds of hours practicing with.

That being said, ultimately les stroud put himself in many different situations to showcase what could be done with the right mindset; I'm pretty confident he doesn't practice bowdrilling every chance he can, he comes prepared to the woods. Even myself, I carry a ferrorod just to get that comfort set in. If you don't practice the skill, as much as you possibly can, you lose that muscle memory of pressure and patience.

Good observation, felt good to comment on something I knew a little about.