I think this is the most important evidence against it. You could parse Quirrel as saying that Harry being Tom Riddle on the map is a surprise and no a trick, and that he is not commenting on himself being Tom Riddle instead of Baba Yaga.
You could also assume that Quirrel is lying about parseltongue. But yeah, I think that drops the probability a lot.
I love this idea in general: but don’t see how he could have faked the map, given:
“Did you tamper with thiss map to achieve thiss ressult, or did it appear before you by ssurprisse?”
“Wass ssurprisse,” replied Professor Quirrell, with an overtone of hissing laughter. “No trickss.”
I think this is the most important evidence against it. You could parse Quirrel as saying that Harry being Tom Riddle on the map is a surprise and no a trick, and that he is not commenting on himself being Tom Riddle instead of Baba Yaga.
You could also assume that Quirrel is lying about parseltongue. But yeah, I think that drops the probability a lot.