I think Glasco has a whole lot of things to manage during a game and thats why I recommended putting either an assistant Coach or a player who is on the bench in charge of making sure subs get checked in and out. Just whatch and say hey Coach we did not check in so and so.
Everyone makes mistakes, but after the second time a new procedure should have been installed to correct it.
But, if it did not happen last game it could very well be fixed already.