The actual results - 10 direct hits with 280mm guns and several damaging near misses - vs 2 hits by 203mm and 17 x 152mm indicate a substantialy more accurate gunnery for AGS.
Exeter's gunnery and firecontrol systems were disabled quickly and early. Reduced to four guns under local control as early 0623, and two guns on local control by 0634, Exeter really had no hope of scoring any further hits.
The two light cruisers were firing in unision using a common fire control solution early on. They were essentially firing 16 gun broadsides. This was when they did most of their damage. However the radio link between them broke down, forcing them to fire separately. From about 0640 the light cruiser fire was directed by Achilles' observation aircraft. It was later determined that the observer mixed up the shell splashes from the two cruisers, so his fall of shot corrections cancelled each other out, with one consistently shooting overs, and the other one consistently shooting short.