The problem isn't a major issue but can cause a nuisance. The primary reason this happens is due to the athlete rocking back too soon and/or pulling the shoulders back behind the bar before it has passed the knees. Instead, the lifter should be patient and keep the shoulders in place (whether directly above the bar or in front) for a longer period of time until the bar has passed the knees. Remaining patient like this video shows also helps the athlete stay in a "hang" position anyway, which is strong stance for many.