Recently, Creepers were changed to actively attack Iron Golems, since Iron Golems had been changed to attack them previously. However, this AI to attack Iron Golems takes priority over the AI for avoiding Ocelots/Cats. A simple way to show this is using this command:

/summon Ozelot ~ ~ ~ {Riding:{id:VillagerGolem}}

When a Creeper is spawned within range, it will run up to the Iron Golem and explode, killing the Ocelot. When considering players, Creepers will always prioritize avoiding Ocelots/Cats over attacking. The AI prioritizing attacking Iron Golems to avoiding Ocelots/Cats is definitely erroneous.