I turned on the watchdog function in my RPi and I did have a freeze once that was properly handled. I recommend enabling it.
Note that this is a standard RPi feature, not unique to OSPi. The wiki contains some instructions on how to set it up. http://rayshobby.net/mediawiki/index.php?title=Set_Up_RPi,_RTC,_WiFi,_Data_Log#Hardware_watchdog
Scott