The answer to the riddle -- whosawit?

[M.Clifford]

No: HPFGUIDX 129762

> TigerPatronus:
> > US Pb PoA (p361): "Like father, like son, Potter! . . . You'd have
> > died like your father, too arrogant to believe you might be
> > mistaken in Black -- now get out of the way, or I will make you. .
> . ." -Snape

> Valky:
> > First lets draw the picture: James is adamant that Sirius would
> > not betray him at the moment (or extremely close to the moment) of
> > his death.
> > Voldemort kills James in a duel.
> > Snape witnesses James unwavering trust in Sirius even when faced
> > with imminent death and/or James actual death.
>
>
> -Mags *delurks*:
> To me, the quote above seems like evidence Snape *wasn't* there, or
> at least that James didn't say anything much if he were - because
> presumably James knew who his Secret Keeper was, right? And it
> wasn't Sirius. Snape, however, apparently believes that it was.
>
> I can picture a fairly convoluted scenario wherein Snape/other
> clueless DE says something like "Black has betrayed you" (not
> knowing the real identity of the spy, and thinking that Sirius is
> the logical choice) and James denying that he would, but
> well...Occam's Razor, and that seems like an unlikely scene to
> posit. Easier (for me, anyway) to believe that Snape just thinks
> that James was dumb to pick Sirius as SK, aided by 13 years of
> hindsight and the fact that he hated them both.
>

Valky:
I promised myself I would not do this, and that I would leave this
vague, but since someone actually delurked to answer... no actually
any excuse will do.. I knew I wouldn't easily resist...

I my defense Occams Razor doesn't cut the scenario that you posit Mags
IMHO. To be fair the quote does say literally that James *was
arrogant* when faced with the notion that Sirius was the spy. 
The character Snape doesn't like to BS about this situation, if he
says he directly observed James arrogant about Sirius at the moment of
his death then why question it? 

And furthermore the oft quoted "I KNOW! Headmaster" that the Potters
were indeed betrayed by Black is a giveaway that Snape dealt with
Godrics Hollow (at least in his own mind) on a more direct level than
other characters did. This does lend weight to the scenario that I
have begun to introduce, however I did promise myself I wouldn't
defend it...