Toz had been frustrated and irritated with how the general and his subordinates had led him to the secret room and what they, especially the general, had done when he finally arrived at the secret room. But emotions didn't cloud his judgment enough to make him miss how obvious it was that they were testing him and his capabilities.
The flashing light went right past the alleyway where the tunnel was several times. If they noticed that Toz's magic was faltering or that he was about to run out of mana, they would have directed him straight to the magic circle instead of continuing to lead him around the base.
And forcing him to wait on the circle and slide through the unnecessarily long tunnel was probably a test of his character and mental abilities. They had to see if he could withstand psychological pressure and whether or not he was claustrophobic.
