After Numba had left Gary alone with the nurse, the woman had asked Gary a few routine questions before attempting to get his blood sample. Biding his time, the green haired teenager had asked for some food, but the medical professional had told him that the doctor ordered her to get the test done first.
With no better idea, the Werewolf told the woman that he really needed to go to the toilet, and with him just having woken up, she understood why he might need to go. Unfortunately for him, she had accompanied him right to the door, and since he stayed inside for over five minutes, the nurse was just about to call the doctor. Naturally, the green haired teenager had quickly left his impromptu hideout.
During that whole time, Gary himself was thinking of a plan, any plan to get him out of the situation, even climbing out of the toilet window, turning into a werewolf and never coming back to the academy again.
In the end, he could think of nothing.