I decided to enumerate all the map errors I could think of.
Name errors: any error in which someone’s name is persistently not what you’d expect.
Quirrell being named Defense Professor.
Anyone (probably Quirrell, maybe Harry) being named Tom Riddle.
Quirrell or Harry being named Heir of Slytherin.
Map errors: any error in which the map itself is drawn incorrectly, or in a way you wouldn’t expect.
The Chamber of Secrets entrance being drawn on the map if/when Quirrell accesses it.
Quirrell being drawn inside a wall if/when Quirrell accesses the Chamber of Secrets.
If Quirrell can become a spirit, Quirrell being drawn inside a wall when he is in fact inside a wall.
Harry being drawn in strange and incorrect places when he’s inside of his trunk.
Name persistence errors: any error in which someone changes names.
Harry changing names while using his “dark side.”
Quirrell switching between Quirinus Quirrell and “Defense Professor,” possibly when Quirrell “rests.”
Quirrell being labeled Salazar Slytherin, particularly when he accesses wards.
Harry being labeled something more commonly associated with Professor Quirrell when he uses his Potterdar.
Multiple dot errors: any error in which one person is in multiple places.
If the Dark Lord can become disembodied (perhaps while Quirrell is “resting”), separate “Quirinus Quirrell” and “Defense Professor” dots in different locations.
Any student with a Time-Turner showing up twice on the map.
As someone suggested earlier, it’s possible that Sirius Black is hiding out as the Weasley owl (the “measured and courteous hoot”). That would fit with Peter Pettigrew being the unfortunate in Azkaban chanting, “I’m not serious.”
It’s also possible that Pettigrew is hiding out somewhere, I suppose, but that doesn’t seem smart.
This also raises the possibility that someone or multiple someones who weren’t ever Marauders using small animagus forms to get around the castle, which could show up funny on the map.
Please note that Dumbledore has used the map, and has commanded it to “find Tom Riddle”. Many of your suggestions would lead Dumbledore to discover something he hasn’t.
This isn’t so. Quirrell was off campus when Dumbledore used the map. The only suggestion that it eliminates, assuming that Quirrell wasn’t using his Potterdar at the time, is the idea that Harry is persistently labeled Tom Riddle.
I decided to enumerate all the map errors I could think of.
Name errors: any error in which someone’s name is persistently not what you’d expect.
Quirrell being named Defense Professor.
Anyone (probably Quirrell, maybe Harry) being named Tom Riddle.
Quirrell or Harry being named Heir of Slytherin.
Map errors: any error in which the map itself is drawn incorrectly, or in a way you wouldn’t expect.
The Chamber of Secrets entrance being drawn on the map if/when Quirrell accesses it.
Quirrell being drawn inside a wall if/when Quirrell accesses the Chamber of Secrets.
If Quirrell can become a spirit, Quirrell being drawn inside a wall when he is in fact inside a wall.
Harry being drawn in strange and incorrect places when he’s inside of his trunk.
Name persistence errors: any error in which someone changes names.
Harry changing names while using his “dark side.”
Quirrell switching between Quirinus Quirrell and “Defense Professor,” possibly when Quirrell “rests.”
Quirrell being labeled Salazar Slytherin, particularly when he accesses wards.
Harry being labeled something more commonly associated with Professor Quirrell when he uses his Potterdar.
Multiple dot errors: any error in which one person is in multiple places.
If the Dark Lord can become disembodied (perhaps while Quirrell is “resting”), separate “Quirinus Quirrell” and “Defense Professor” dots in different locations.
Any student with a Time-Turner showing up twice on the map.
As someone suggested earlier, it’s possible that Sirius Black is hiding out as the Weasley owl (the “measured and courteous hoot”). That would fit with Peter Pettigrew being the unfortunate in Azkaban chanting, “I’m not serious.”
It’s also possible that Pettigrew is hiding out somewhere, I suppose, but that doesn’t seem smart.
This also raises the possibility that someone or multiple someones who weren’t ever Marauders using small animagus forms to get around the castle, which could show up funny on the map.
We now also potentially have
A hidden troll is marked “Defense Professor”.
Please note that Dumbledore has used the map, and has commanded it to “find Tom Riddle”. Many of your suggestions would lead Dumbledore to discover something he hasn’t.
This isn’t so. Quirrell was off campus when Dumbledore used the map. The only suggestion that it eliminates, assuming that Quirrell wasn’t using his Potterdar at the time, is the idea that Harry is persistently labeled Tom Riddle.