iOS: Device disabled after entering wrong passcode
Using iPhone/iPad Recovery Mode
You must already know the passcode. Use Find My iPhone App and place disabled iPad in "Lost Mode". Open iTunes and connect disabled iPad on your workstation. Upon identifying your iPad, go to File --> Devices --> Back Up. It will fail and give you a message that the iPad is locked. Go to Devices --> Sync "Name iPad" and keep an eye on the iPad. As iTunes attemtps to synchronize, it will unlock it and display that the iPad is in "Lost Mode", Swipe to Unlock. The passcode keypad will now come up and you can unlock it. Unlock it and immediately disonnect the iPad from your workstation.
This just worked for me and probably saved my job after an executive in the company inadvertently locked his iPad. iPad's must already be registered within Find My iPhone app. Not sure if the step to Back Up is necessary, it just happens to be what I did first. No data loss, iPad returns to previous state prior to being locked.