yard after dark unless you are just throwing something back over the fence real quick, but even that is weird, and I would just knock and ask them to throw it over. The fact that he's a few houses down from you is concerning. And you said that you think he saw the camera? He might know he was filmed and is tripping right now. But this likely isn't the first time he's snuck in someones yard to peep.
He's also a member which makes this really sad.
I don't know if this is appropriate but could you post the video for us to see?
Last week I had a random facebook message. I opened it and it was my literal next-door neighbor asking me to throw their football back over the fence. Sad that she couldn't just knock.