Is it possible that Richard and Rachel could be in the cafeteria footage?

hey yall, so i remember seeing somewhere that one of the things rachel had on her when she died was a receipt from the cafeteria that morning (she got a carton of milk). would it be possible to find her and possibly richard in the cafeteria footage it if you looked hard enough?

11:32:36 ID 10512265 Rachel Scott – 1175 (1)

subtract 10 minutes to coincide with timeline so she would have been there around 11:22 AM

Always one of the more curious facts of the case. What is the reasoning for 11:19 as the start, then? Why not subtract fifteen? (honest question, not rhetorical). Does seem like people are already reacting by 11:22.