By "bioerror", I mean something which has the same effect as a terror attack, but rises from inadvertance rather than evil intent.
Covid19 might be due to an accidental lab leak, which seems to qualify here.
I'm not saying that Rees has eloquently made a case here on his longbet. I'm saying that he won the bet, and he might be more correct in his thinking than Pinker. Your hypotheses don't have to be well-founded to be correct; the converse is true as well.
If providing evidence for one's beliefs is a sign of irrational bias, well, I guess that explains a lot.
Thus far, the experimental evidence suggests Rees is correct. Pinker had evidence for his hypothesis, but it led him to wager incorrectly. Of course, it's an n of 1, so we haven't disproved either.