With Lena you can consult the activity related to a file/folder: it gives you an overview (as a list) of all the actions related to this element. Right click with on the folder/file and select → View activity.

A window shows up, listing of all the past operations related to this file/folder.

With, from top to bottom :

1. A visualization graph of activities per category.
2. Fields to filter activities by date, types of activities and users.
3. The detailed list of activities (when, who, what), extra information is available by hovering/clicking on a line.

The deletion of a file appears in activity of the folder which contained the file. From there you can undo the deletion of the file by simply looking for the deletion event and using the restore action on the same line.