Nokia Nseries :: 603 Unlocked Without Security Code?

I've security code set on my 603, but somehow my 7 year son could get through (and he doesn't know the passcode). I had put it on charging on power plug. He somehow managed to get in. When my wife notice him fiddling up with the phone, it showed up message asking whether to initiate an emergency call. She took it away from my son, only to notice that it was reset to factory settings

Not sure how it would have happened. How in the heavens could he get past security code. I've my corporate email account set and it doesn't allow to turn security code off for that reason.

I could recover from 7 day old backup. Some sms are lost and all app need to be reinstalled now. Many standard app that came in bundled didn't come back after recovering from backup.