Continuity mistake: When Keating tells the students to draw a graph, they all follow him step by step. For a specific shot, Meeks mimics what Keating writes on the board and draws a bar graph and colours it. Problem is, Keating does not draw the bar and colour it until a shot later. The movie should have been edited the other way around.
Continuity mistake: During the final scene when the boys stand up on their desks, the boy with dark brown hair stands up twice. After Pitts stands up we see him contemplating, then when Meeks stands up he is visible standing up already, but then seconds later he stands up again.
Chosen answer: He is just trying to get something to help wash the taste of vomit out of Todd's mouth.
Macalou