If someone would like to read my official rules on critical hits, fumbles and friendly fire, see this page.
There's always something unaccounted for. It occurs to me that some sort of rule should be made regarding the final location of thrown weapons - I've never had good rules for this and I should make some. It's not an easy fix, however. Usually, I just play that the missed weapons are "somewhere" in the line of fire, typically thrown past the target. Hmf. I've not had a player complain, but a good rule for it would be better.