While I agree that a person may startle at pain, I know my first reaction is to move away, not strike back. I do think striking out physically is an aggressive reaction.

Things happen. I have had many accidental injuries caused to me by my kids, and I don't hit them when that happens. For example, being bitten by my 18 month old while he was nursing. He was falling asleep and I guess he was dreaming and he clenched his teeth.(If you think a parakeet bite hurts, try that sometime. Not fun.) Anyway, I did yelp, and startle him, but I didn't want to hit him.

I am hopeful that the op is working with the bird and will now be very careful to guard against physical discipline, reactionary or not, in the future.