If we cut ourselves when preparing food, unless that food is going to be cooked thoroughly, should it be tossed?
There are a couple of things to consider here but it shouldn't be too difficult to cover them all.

If it is just you that is eating it. No problem. You are already exposed to your own pathogens. We've all tasted our own blood. There shouldn't be any real risk here.

If it isn't just you: Stop!

Under no circumstances should you feed me something I have no reasonable reason to suspect is in the food. I am not okay with this even if you do cook it. Are you willing to go into the other room and ask your guests how they feel about human blood in the chicken marinade? If it sounds like an awkward question that you don't want to ask, then throw it out.

That said, there are many foods out there with blood in them. Blood sausage, blood pudding, blood soup and more. I'm not certain of any risks that are peculiar to human blood specifically being consumed. There isn't a lot of research from credible sources out there. I personally would not rely on it being safe just because it can be done safely with pigs blood.

In short, if you cut yourself prepping a salad and don't notice til you've tossed it all together, throw it out. This unequivocally falls under the when in doubt, throw it out clause.