It was barbless, I use barbless most of the time.

You have some good points that make sense about the hook making a bigger hole and possible causing more infection. which I agree could be a factor.

On the other side its not feasable to use anything smaller than 2/0 when using 6" plastic worms and rags and such. Not in my opinion anyways

I dont agree that holding a fish out of water for a few seconds with extreme care is the same as dragging a fish up onto the rocks. than kicking it back into the water when people figure out its wild, (which happens most of the time out here).

Plain and simple hooks poke holes in fishes mouths and do damage. I havent seen that it makes much difference in my experience as far as hook size goes. Barbed vs barbless or bait vs no bait. To light of gear vs the right gear. Using a nett vs no nett. These are all factors that in my opinion play a much larger role in the survival of the fish after release.