Whenever possible, videotape students completing simulations--and retain the tapes. It's a good training tool, and it is excellent insurance against a failure-to-train lawsuit. Just as cruiser-mounted video cameras can show a defendant's drunken behavior prior to an arrest--in stark contrast to his sober courtroom demeanor, a video of a student going through a simulation can save a lot of "he said--she said" arguments about what really happened.
An incidental benefit of videotaping student performance in simulations is that it encourages the agency to think twice about retaining an employee who cannot perform to standards. Training records are subject to discovery, and a video documenting inadequate performance would be powerful ammunition in the hands of a plaintiff's attorney.
Remember, conducting training is only half your job--documenting it well is the other half. If you don't do the second half, you might as well not have done the first. The old saying is just as true for training officers as for patrol officers handling calls on the street: "If it's not written down, it didn't happen."