David is a music professional who has licensed music for film and TV before. He knows about licensing and such. And, I don't think he'd post it if it wasn't legit. He'd be sending a C&D letter.
Sometimes if it's a not for profit film, you'll send stuff and hope they use it. Then you count on performance royalties to give you a little income. That is if they submit a cue sheet to the PRO's. It's also free advertising. Someone could hear it and want something for another project.
I sent an entire library of music to a newsmagazine show. Gave them a gratis sync and master license, just make sure it's on the cue sheet. Only knew it was used when it aired, or when it showed up on my PRO domestic distribution. 
Best not to jump to conclusions until you have all the facts.
Last edited: Jan 13, 2018