serious you are a genius! (See how pretty 'serious' and 'genius' look together?!) Your thoughts and reason about the fact that someone must have witnessed the Godric Hollow carry-on was great!! Ta.

psyduck; you are genius too!! Off course the info given to Hagrid about what happened that night was sketchy because the witness caot nnhave been in the house (I think).

Hagrid got this info second-hand from someone watching outside, Hagrid was not there himself. Can you imagine Hagrid sitting in a bush passively watching a murder happen? Can you imagine Hagrid finding a bush big enough to sit behind?

Hagrid DID know something about that night. He knew that Harry's parents died before the final assault on Harry. Hagrid never suggests any other scenario but the one he gves. He never hints that MAYBE Voldy skulked around the house's outside windows to find a sleeping Harry in his cot or that Voldy probably just blew up the whole house and Harry miraculosly survived. Hagrid never says 'Voldemort tried to kill your family and only you survived'. His words are more particular. Hagrid says:
'You-know-how killed 'em. An' then - and this is the real myst'ry of the thing- he tried to kill you, too.'
How else would Hagrid have known that James and Lily were killed first AND THEN Voldy turned to kill Harry, unless he was told by someone?? Therefore, Hagrids was told how it went down night.

K. So who's the witness??
Petigrew's an option because he knew where it was gonna happen (secret keeper 'n all).
Snape. All the reasons given in above posts.
Who else????