I agree. HOWEVER, the AI does load ammo, i've seen em load heavy clip into the gatling gun.
pics or it didn't happen
No I've seen it too. Thought it was weird when I first saw it but sure enough. Think its some rare bug. Haven't seen it for a long time and it wouldn't happen consistently. My guess would be the AI pathing isn't that much different than that for engineers. Remember AI engineers can change between spanner, mallet, extinguish. What would be stopping a gunner from doing the same thing other than maybe there is no instructions for it? It wouldn't surprise me if at times the AI has a brain fart and decides to change ammo.
Think about it, why does the AI unload guns when it gets on them? It is changing ammo. Now it didn't used to do this. Used to see AI jumping on guns and using them with whatever ammo was preloaded. Then it would reload with standard when the clip would be up. My guess is, Muse has been tweaking a little. Remember they did state there would be an AI director that would be required for COOP + Adventure mode. AI being smart with ammo would be a step towards that I'd imagine.