General note on stealth; you don't need to roll over and over.
As long as you don't attack, make noise or move more than 2 square you can remain hidden as long as you have cover or concealment. Therefore Barrion is still hidden since he just used his surprise round to curse the wolf.
Concerning your roll, I am confused. You indicate +2 to hit and damage in the notes but the powerful charge feat only gives +2 to damage and bull rush.
Yet you used +13 to attack, which is the correct attack bonus for a charge by Dagran... (+12 normal, +1 charge). So...
When doing the status report I initially noted you at 20/56 and Dagran at 59/66. So I wondered why the hell there was 10 points of difference between the two defender when they have the same constitution. Tougness only accounts for 5.