Oh yes, definitely. It can be a classic example of more haste, less time. A good turnaround manager will be 100% sure of both passenger and baggage status before giving the green light but the sort of thing that happens is that someone's baggage is loaded, the ground agent think everyone is boarded, the aircraft pushes back, and then Mr X runs up to the gate and says "am I too late?". That's the worst of all scenarios since he isn't allowed to travel at this point and his bag also has to be offloaded.