I know my answer will sound extreme, but when our saw messes up and cuts a beam short(even a 1/2"), we splice a foot back on and then UT the joint, and cut the beam back to the correct length. (depends on the end condition, this would be for a plain end with no end connections)
Word of caution here, if you do get a splice approved, make sure the EOR tells you where he will allow the splice to be....if it is close to a connection, he might ask that you move the splice further back down the beam and splice on a longer section.
Might better pose this question of repairing by buttering the end to the EOR...BEFORE you attempt any type of repair.