Figured it out for those who stumble upon this. ACL and CameraEX both exhibited the same behavior, and were both resolved in the same manner.
Prior to cam.takepicture, I had always called panelpreview.removeview. Though perhaps misguided, it did seem to free up resources while the image was manipulated and it worked for every user I had, and removed some issues (it seemed) I had with users with real poor hardware.
Moving the panelpreview.removeview to after cam.release (post picture) solved the problem for 4.3 and 4.4 users.