Yes, if there is a recognizable person in any of your video clips, then you will need to have a signed model release on file from that person. Lightstock does not require you to upload model releases with your content, but you are required to have one on file should it ever be needed. It is ultimately your responsibility to have the model release on file.
Here is a link to our recommended model release form - Model Release
Download the app, “Easy Release - Model Release App” on your mobile device. It’s a great alternative to paper copies!