You might be curious to create an Activity Record with start and end times that you can figure out.
And see what distance and calorie burn was associated with those 600 steps.
You'll likely find it very small and meaningless compared to the day in general.
Might allow you to take the few calories, knowing that if no steps were seen, you'd be given a sleeping rate calorie burn.
But I'll bet you burned more calories cleaning the oven standing there, then when sleeping.