In the classroom when the young Rimmer receives the note from the female student sitting next to him that he is a guinea pig, Rimmer writes his reply
on the page but when seeing from the viewers point of view, the page doesn't have the previous message, only Rimmer's message. Rimmer is not shown turning to a new page so its assumed he is writing on the same page as the female student's message.
Lister teases Rimmer about his last words being "Mummy, mummy" (or, more accurately, "M..") and Rimmer doesn't disagree. Rimmer's actual last words, established earlier in the series, are "Gazpacho soup!?".