Does Google Drive secretly delete files?

Today, my wife had an incident where one of her spreadsheets on Google Drive was deleted, not by her. It's her customer list, CRM and life's work, so it was a pretty important spreadsheet.

To ensure she is not making any mistakes or human errors, I verified her Google Drive history using its audit feature and search. Indeed, the spreadsheet link was there in her browser, but when accessed, it gave an error "This file has been deleted." Accessed two days ago. But the file was not in the Google Drive trash bin, nor did it appear in the search. There was no record of deletion of the file, but when accessed, Drive told the file has been deleted.

When we contacted Google support, they just said "the file is now there" and it magically reappeared. This is spooky, and also worrisome if files can be disappear and no explanation is given.

Does Google Drive secretly delete files, and for what reason?