It would appear so, yes.
Pg. 63 states:
If a unit is destroyed for any reason, all friendly units within 6" must immediately test for panic.
That coupled with
pg. 25
As soon as a fleeing unit moves into base contact with the battlefield edge, it flees the battle and does not return - we assume that its warriors scatter to the four winds. Such a unit counts as destroyed for all intents and, more importantly, all rules purposes.