I've had eggs pipping when I went into lockdown, but never had one hatched out that early. There are different things that can cause then to be a little early, but if it is that early, it means your incubating temperature was too high. If you have a forced air incubator, it means that all your eggs should hatch pretty soon. If is is a still air, it is possible you had a hot spot in your incubator and that one or just a few others will be that early and somne others could be later. But expect them all pretty soon.
Your risk in opening the incubator is the eggs could possibly become shrink-wrapped. If you have not yet gone into lockdown, that means you have not yet raised the humidity so you can see that shrink-wrap does not happen each and every time. It's something that can happen, not something that will every time.
I'd quit turning and raise the humidity. If you can do that without opening the incubator, I'd do it that way. If you have to open the incubator to do that, then do it as quickly as you can without damaging the eggs. Don't get in a blind rush and cause an accident. When you add water, use warm water about 100 degrees F so the humidity get sback up prety quickly.
I would not remove the chick until hatch was over or at least a couple of days. It will be fine. And maintain temperature.
Good luck! It's not the best of circumstances but you already have some success.
Editted to add: It's possible that egg starter to develop before it went into the incubator if it was stored for a while at pretty warm temperatures, maybe even in the 80's F. I'd still do as above.
