Not only not starting correctly but also weak whistles and not standing in front of the kids when they start. Not sure there is a rule that the ref has to stand directly in front but we teach the kids to look for the ref so they can go right off the whistle. Kind of hard to do when the ref is off to one side or even behind the wrestlers when he blows the whistle.
The rules do not specify where the official must be when the whistle is blown, and the reason we as officials do move around on the mat is to look for incorrect starting positions (ie, the leg between the down wrestlers legs, leg up against his butt, head off the midline, etc.), also so the wrestlers cannot "jump" the whistle by the official doing the same thing every time, they should go off the whistle and the whistle alone, no visual cues. This is why the official will sometimes walk around or even be behind the wrestlers when the whistle is blown, but will usually come around to the front very quickly to continue his match duties.
