Did you have any 'instructions' when you did the initial drywall job? Part of the job requires mudding in tape/mesh. Did you use it?
Before you make any repairs, buy yourself a good, general home improvement book from, say, Time-Life or Reader's Digest. You'll have to remove the orange peel from the damaged area to do the fix. Then, re-spray. It's possible there will be a noticable difference between the 2 applications. Talk to the contractor about this.
If you did use tape, it's possible that the weight of the spatter is pulling down the ceiling. Again, tell the pro how thick your drywall is and 'where' you put your screws. He may have a different recommendation for drywall thickness and screws.