I'm not certain, but in the picture from the Forbes article the lock looks exactly like the kind used on many doors in my university - the shape is exactly the same, and ours had the same type of electrical connector in the same place at the bottom of the lock. I remember because I considered attacking this interface before noticing the torx security screw next to the connector; removing this screw allows the panel covering the bottom part of the lock to be removed (the edge of this panel is visible in the Forbes photo), exposing the bolt mechanism of the lock. Turning this mechanism one way opened the lock, turning it the other double-locked it so it couldn't be opened with the proper keycard.
I wonder if any HN readers have access to an Onity lock to check whether this method works on them?
I'm looking at my test lock (which doesn't have panels on it) and it looks to me that there's no way you could access the lock mechanism from the battery panel. With the HT locks I've played with, the locking mechanism sits inside the door, between the lock itself (with the circuit board, card reader, batteries, etc) and the back plate containing the deadbolt and such. Don't think it's vulnerable to what you're describing. However, it should be noted that if it's used in the university, it's almost definitely the Integra/CT line from Onity, which is different.
I wonder if any HN readers have access to an Onity lock to check whether this method works on them?