They also made sloppy mistakes like naming the Proven owner's partner un-redacted in a document they submitted to the court (which is then available through legal search engines). If they were concerned with privacy they could easily have withheld her name.
The one time security through obscurity would have helped them?
That would be more like: shuffling that document randomly between other documents, or using white font on a white page in Word.
Obscurity is often a valid security tactic, just not all the time and never by itself.