If Hagrid was accused of opening the Chamber of Secrets in Harry Potter and the Chamber of Secrets, where exactly was he accused? I have had this question on my mind, and I haven't been able to get the book to find the answer.
We don't see that scene in the books,largely because it happened a very long time ago and isn't one of the memories that Harry explores in the Pensieve, but we do get Tom Riddle's account of the event and what transpired afterwards.
In brief, Tom falsely accused Hagrid of opening the chamber. Headmaster Dippet believed him and Hagrid was confronted with this (presumably in the Headmaster's office, which seems a logical place for a meeting of this sort), failed to convince the Headmaster of his innocence and was expelled from the school but retained as a junior staff member, which in hindsight seems really odd if they thought he was such a risk.
‘Hagrid’s my friend,’ said Harry, his voice now shaking. ‘And you framed him, didn’t you? I thought you made a mistake, but –’
Riddle laughed his high laugh again.
‘It was my word against Hagrid’s, Harry. Well, you can imagine how it looked to old Armando Dippet. On the one hand, Tom Riddle, poor but brilliant, parentless but so brave, school Prefect, model student; on the other hand, big, blundering Hagrid, in trouble every other week, trying to raise werewolf cubs under his bed, sneaking off to the Forbidden Forest to wrestle trolls. But I admit, even I was surprised how well the plan worked. I thought someone must realise that Hagrid couldn’t possibly be the heir of Slytherin. It had taken me five whole years to find out everything I could about the Chamber of Secrets and discover the secret entrance … as though Hagrid had the brains, or the power!
‘Only the Transfiguration teacher, Dumbledore, seemed to think Hagrid was innocent. He persuaded Dippet to keep Hagrid and train him as gamekeeper. Yes, I think Dumbledore might have guessed. Dumbledore never seemed to like me as much as the other teachers did …’