So 8 donors had polluted blood? That sounds about right.

Probably not...there's lots of other criteria...as an example, you have to provide the entire pint inside a time limit (some folks don't drain all that well

or they can't accept it and so on...
OK. I thought it was more like questions about your past; and if you could not remember the 70s at all, your blood was suspect.

I had donated blood (and had it drawn for physicals) many, many times, but last time, I was woozy in the early morning, and as the blood drained out, I turned pure white and went into a kind of septic shock (and thought I was dying)(they actually got the paddles ready). They asked me if I had needle aversion, and I said not that I know of. I had to go home from work and was very sick and nauseous the rest of the day.
That was as unpleasant as anything I ever went through, so I'm not donating anymore.
The only thing similar ever happened to me was when I had to get all my expired overseas military immunizations for the Middle East at the same time (they usually spread it out over two weeks, at least). They went to work on both arms, and the next thing I knew, I was on the floor drooling with people standing over me asking questions, and I had to be drug out of the room and to a bed. I was told I was setting a poor example for all the junior enlisted in line behind me, and I said........ WELL EXCUSE ME!!! (
is it OK if I puke in this waste basket, or would the floor be OK?). (DPT, both halves of yellow fever, cholera, malaria, and a couple more). I had a touch of yellow fever for the next day and a half. Lovely. Of course, we didn't deploy overseas anyway.... but we were not gonna get any foreign diseases for the next few years.