something that raises my hackles probably more than strictly necessary: when people say "omg, thing X happened? that's so outrageous! if aspect Y had been different, this would never have happened, proving that people are biased along that axis" (e.g. "he never would have gotten away with this if he were a woman").

this is in some sense just one particular kind of appeal to fictional / imaginary evidence, but this one in particular bothers me because, a moment ago you probably would have predicted that thing X wouldn't happen either? so the fact that you still think a slightly modified X wouldn't happen doesn't feel that compelling to me, like maybe you're just not updating enough

(not all appeals to imaginary evidence are invalid, when they're good they're called "thought experiments", but often they're not good)