Help - Sack or No Sack - Panthers/Giants

[Ron76]

Could you please help me out with my questions below?

At 12:58 of th 3rd quarter of last weeks Giants/Panthers game there was a supposed sack of Jake Delhomme by Kyle Washington. Almost all sites list this as a sack except for our YAHOO Fantasy Football league which considers it a -4 yard rush. Whether or not Jake Delhome was sacked on the play will decide the winner of our league. Weird huh!

1) Is there any remote chance someone actually saw this play and can tell me whether it was a sack or not? I cannot find pictures or video anywhere.
2) I am trying to justify how a 4 yard loss running by a QB would NOT be a sack. Any ideas? If he was chased out of bounds 4 yards behind the line of scrimmage, is that a sack?

I know this is a lot. Thanks for your help.
Ron