Can You See the Tactic?

I was watching one of IM Daniel Rensch's videos (this video), and since I don't have a Diamond Membership, I didn't see the whole video. But the problem that I saw was interesting:

 He didn't get the problem right, as you can see by his expression of utter annoyance. 

Now let's see if we're thinking along the same lines. I'll start the puzzle off where IM Rensch got it wrong.