The attempt at step up is all wrong too. By lingering and taking so much time to do it, only confuses the bird. The bird doesn't look like it bit, looks like it was leaning to get a grip while the hand was getting pulled back away. Also, I found that Jardine's babies are for some reason worse than most species at stepping up and you gotta just grab them and carry them around.
But let me tell you, if you guys continue the kind of stuff you are doing, that bird will become a real biter. I definitely see a lot of encouragement for nibbling behavior. For now it's not a big deal but if you continue to react like this to bites, the bird will bite for giggles. Definitely need some more confidence and not to react to it.
BTW if you're so scared of those little nips, just have the bird step up on a stick/perch. You want it consistently stepping up... not consistently reacting/encouraging further nipping.






