You are correct, that the manual doesn't specifically say it can operate without coolant (now that I re-read it). What it does is active fail safe mode, then will shut the engine off once the temperature goes above another (higher) threshold. So I guess if coolant is completely gone (instead of just low), you may be able to drive for a few minutes then be shut down for a while before driving again (the main purpose is to give you enough time to find a safe spot to stop).