When judging the danger posed by this particular plot, the temptation may be to ask how many more of our Afghan compatriots are plotting against the government we are trying to stabilize.
An alternative metric is to ask how many similar penetrations of the enemy command and control structure we have managed to make. Could we stage a similarly disruptive attack using people within, say, the Haqqani network or the Quetta Shura?
If the answer is no -- and my sense is that the answer is, in fact, "no" -- then we need to consider ourselves outmaneuvered. This kind of war is more similar than it is sometimes thought to be to classic maneuver warfare, except that the field of maneuver is not marked by flags and uniforms but by the real loyalties of the people. What you are seeing here is evidence that we have been flanked.
That leaves us with the usual options when you find that your enemy has successfully flanked your position. It is possible to withdraw to a stronger position, call for reinforcements and try to hold until they arrive, or to attempt a counterflank, or to attempt to overcome the enemy advantage with fires, or to surrender. There will be no more reinforcements. If, as it appears, we lack the capacity for a counterflank, and surrender is certainly off the table, that leaves us with the options of fire and withdrawal. These are not necessarily exclusive, although evidence is that our fire support is under increased pressure.
The fighting season hasn't even properly begun as yet. Expect this to be a hot one, especially in areas where the Afghan troops can be separated from NATO forces.