Não, porque o Shrieking Shack está localizado em Hogsmeade, não em Hogwarts.
Snape was slightly breathless, but his face was full of suppressed triumph. 'You're wondering, perhaps, how I knew you were here?. he said, his eyes glittering. 'I've just been to your office, Lupin. You forgot to take your Potion tonight, so I took a gobletful along. And very lucky I did ... lucky for me, I mean. Lying on your desk was a certain map. One glance at it told me all I needed to know. I saw you running along this passeway and out of sight.'
" Fora da vista ": O mapa terminou aí. Mostrou apenas os compostos de Hogwarts e não além disso. The Shrieking Shack é uma casa abandonada em Hogsmeade .
Assim, Snape nunca viu Harry, Ron, Hermione, Sirius ou Pettigrew no mapa naquela época, porque eles não estavam tecnicamente no território de Hogwarts (que o mapa cobria).