A rare event that has happened in my game more often then I would expect is a player and or me the GM roll the exact same crit as has been rolled before, so in this case do you simply add the two together, increase the results or take it as a case by case basis?
In my game I have done all of the above depending on where I was understanding the game, now I am in the case by case basis group.
Example:
A number of times the players have rolled a crit that gave a large bleed result on a larger and or super large creature, in this case depending on the creature and where the attacks came from I may or may not double the bleed per round but give extra bleed this round. But again there was one time I increased the total bleeding per round to x3 instead of x2 as it made sense per the weapon used, attack description and environment of the combat.
Example:
Cracked bone: -10 + other stuff, if rolled again do you just do -20 + x2 other stuff or do you say the area is already damaged and thus it is easier to damage so I will do -30 + x2.5 other stuff?
MDC