I've never heard of or seen a properly operating M4 or any SureFire LA produce smoke!
Better send the LA back to SF for inspection and maybe the turbohead too if its appearance has been changed as a result. Personally, I don't mind if a bulb blows once in a while as long as it doesn't damage or leave its trace on something as expensive as a turbohead.
Out of interest though, could you describe the state of the bulb and under what conditions the smoke becomes visible?