I've noticed the same thing on multiple occasions by the same person. They are screwing themselfs when it comes to rolling over to the next flight and everyone behind them. I just haven't been lucky enough to run into the individual yet to talk to them and let them know. If agree with going to the union first and eventually management if needed but pulling them to the side and educating them first may be a better answer. On a side note the D2 to D1 switch at the last minute and taking the JS is getting really old guys....