It is conceivable that a situation occurs where both players agree a Panic test is in order, even though the rules don't strictly require it. This is most likely to happen if fighting a scenario you have invented, perhaps where ambushers spring a trap, where boulders are thrown from cliffs, or some such circumstance which the players have contrived.

If both players agree a Panic test can be taken to represent the unsettling situation the unit is in.