LOl
Well it depends on what they are talking about. If he is dropping his elbow then there is reason to correct it, and I would correct it fast.
If what they are talking about is his follow through and the tip is going downward towards the table, then that is a good thing.
The only time the cue has to be level is when you actually strike the cue ball. If it is dipping down slightly after striking it, that is perfectly normal with the pendelum stroke.
If however it is dipping prior to contact of the cue ball then it could be a problem.