[Mobhack]

A spotter (and the AOP unit was probably a spotter for something) will have its indirect/area target hex (IDF hex) set to the hex it fired/spotted indirect/area at last.

Guess what - Z fire is direct area fire - so the IDF hex will be shifted to the Z fire target hex if a unit fires DAF.

This may not be a good idea for AOP units, as it may mean that any indirect arty called in onto a hex is no longer considered on target for that hex even if still in LOS. So best not to do not do DAF with AOP units, really.

Cheers
Andy