One of the lessons that many have learned is that material is usually not learned in one sitting. It takes some repetition, not just a once through.
This would imply that some form of follow-up, either by the instructor or a supervisor, is in order to help firmly implant the lessons that are supposed to be learned. For some training this may not be the issue, so this concern can be dismissed. But for others, it may be wise to explore just how to build in a form of reinforcement of the lessons taught.