Great report as always! It's fun to see the Blood Bowl objective mixed in even if it probably costed you the game.
As far as the re-roll saved vs failed thing goes, I know most people have been playing that they cancel which makes a type of sense. I worked it out mathematically to see the differences between the methods if anybody's interested.
MATH(HAMMER)
No Re-roll
chance = x/6, where x is the amount of faces of the die which would allow you to pass
for example a 2+ save would be 5/6 because you pass if you roll a 2, 3, 4, 5 or 6 and fail on a 1.
Double Re-roll
chance = (x/6)(x/6) + [(6-x)/6](x/6)
= (x/6)[x/6 + (6-x)/6]
= (x/6)[(x-x+6)/6]
= (x/6)(6/6)
= (x/6)(1)
= (x/6)
The first equation is the chance to pass, which is then re-rolled added to the chance to re-roll a failed save. As you can see, the chance to pass the save is identical so it doesn't matter whether you decided to do a double re-roll or just cancel out the rolls mathematically. It is important that you agree to one method before you start rolling dice or else you can manipulate the dice pools to your advantage once they've been rolled.