As someone pointed out on Reddit, it’s pretty suspicious that Harry figured everything out almost immediately after Snape hit him with a “Dispel Confusion”.
This would also neatly explain why Quirrelmort didn’t see this coming “Snape does his level best to help Harry Potter” does not seem like the kind of outcome Q would consider very likely, so his overly complicated plot going off the rails there is perfectly reasonable.
As someone pointed out on Reddit, it’s pretty suspicious that Harry figured everything out almost immediately after Snape hit him with a “Dispel Confusion”.
This would also neatly explain why Quirrelmort didn’t see this coming “Snape does his level best to help Harry Potter” does not seem like the kind of outcome Q would consider very likely, so his overly complicated plot going off the rails there is perfectly reasonable.