A lot of advice about storing sensitive media stops at encryption. That is understandable, because encryption is easy to describe and easy to market. But in practice, people do not just store videos. They review them, scrub through them, compare versions, capture stills, save clips, and occasionally export a file for a specific handoff.
That is where supposedly secure setups often break down. The file may begin life in an encrypted container, but the working process around it still depends on Finder folders, desktop screenshots, temporary exports, and media tools that were never designed around a privacy boundary.
For anyone handling private recordings, internal demos, research footage, legal material, or personal archives, the problem is not only protecting the resting file. The problem is keeping the whole working loop from turning back into loose copies.