The article says that certain other techniques weren't demonstrated because they were "too sensitive to show to the Defcon audience before giving Kaba a chance to fix the problems." What is worse than a whack on the top opening it?
I'd assume ways to fake the access logs. It's bad to allow unauthorized access, but it's really bad to allow unauthorized access that appears to be authorized (a great vector for framing people).
What do the logs look like when the door is opened with a mallet though? If the access isn't logged because there was no card swipe, then the last person to access the door could get blamed/framed.
Ways to bypass the lock and leave no evidence that the lock was bypassed are much worse.
When an ameteur picks a lock it is very easy to inspect the pins and see if they have been manipulated by something other than the key. I imagine that the rubber mallet technique leaves evidence of malicious manipulation behind.
