Youd also not position your medic HQ behind your AA gun as to not create that scenario.
Its a lot better than a plane crashing on your medic HQ by pure random.
that's pretty much impossible. draw a line from the flakHQ to the med truck; that's what my plane will fly. the only RNG there is when it get's shot down and whether or not it falls into the truck (no idea if the fall distance is random or not). only way to prevent that would be to put the med truck way away from the flakHQ but then you don't have that close to impenetrable strong point.