Motherboard:

At issue is a feature in Premiere Pro called clean cache. Editing video takes up a lot of hard drive space as video editing software creates various redundancies and backups during the editing process. Programs such as Premiere Pro store those redundancies in a cache and, once a project is finished, users can clear that cache to free up disk space.

The knee-jerk reaction here? Why didn’t you backup your work? Why depend on Adobe’s backup process?

And those are probably fair questions. But the complaint seems more nuanced than that:

“The ‘Clean Cache’ command permanently deleted substantial and numerous Files and Data that were not within the ‘Media Cache’ folder or any of its subdirectories, including but not limited to Files and Data that had never been associated with [Premiere Pro]”

And:

The mass deletion isn’t a one off and Cooper likely isn’t the only user effected. Adobe itself acknowledged the bug. “With 11.1.1, only files that are within the Media Cache folder’s subdirectories will be deleted,” a blog post from Adobe said when they fixed the bug. “Files that sit next to it will no longer be affected. However, we still strongly recommend keeping the Media Cache folder separate from your original media.”

From Adobe post on unintended deletion:

Premiere Pro CC 2017 (11.1) introduced a new feature to manage and automatically remove aging and unnecessary media cache files. This feature was designed to assist users in managing existing project media cache files more easily. In the default location for media cache preferences, there is no issue. However, incorrect usage of this feature has the potential for unintentional file deletion.

Whose fault is this loss? Ultimately, I suspect a backup would have saved the day, and will be at the heart of Adobe’s response to this lawsuit.