I was making a vegan cake for some carnist friends. While chopping fruits, I accidentally cut my finger. Some blood came out, but only after I'd stepped away from the chopping board with the fruit on it. My friends insisted that I had to throw out the cake dough, because of the hygiene risk, which I thought was strange, given that they themselves eat flesh on a daily basis. They even suggested that the dough may have been contaminated through the air.
Is there any reason to believe that it's more dangerous in any way to ingest human blood that non-human blood, or is this pure speciesist irrationality?