I think Mini-D pretty much said it best. What makes you think that it wasn't the Dar Bar that gave away your mission? As soon as you see a large enemy 'dar bar in a sector, you know it's a mission inbound and the way most people fly in here, it's very easy to predict their route and then set up an interception.
I guess it's easier to blame others for a failed mission than on yourself.
ack-ack