A scientist or archeologist finds some really old thing and they mess around with it too much and unleash a plague on the planet. I think we could all do with not having another plague right now.
I'm sure it's all fine and that when they say "life" they mean micro organisms but at the same time, I will admit I worry a little bit whenever we start talking about messing around with things like this.
Let us be optimistic at first. Probably they know what they are doing. Probably they do this in a high secure and highly controlled environment. Probably they also know that a virus or a parasite, or anything similar is a possibility. Or at least hopefully. Because it is more than 800 million years old, it can be anything. Maybe something that we currently do not even know.
An environmental organism that has never seen a human is not going to have the mechanism to get inside of us and cause disease
How can a scientist say something like this? This is foolish. I am not a scientist, but I still know that every microscopic thing can get inside of us. And who knows? Maybe it does not even need to get inside of us to cause disease.
There are thins that I have not seen so far, but I could still get inside of them, if I would see them. Unless something physically blocks me. But this is obviously not the case in the case of microscopic things. They can easily enter the human body.
If it is more than 800 years old, and it still lives in a rock, then maybe it would be best to not crack that rock open, nor mess with it in any way. Who knows what that is? It can be very dangerous to living organisms, including humans.