I'd say both, the woman for not looking and the man for not being nice enough to put it down.

I agree I would say both.

I believe it is a bit rude for a man to leave the seat up.

I also believe that you should be a bit more careful and look before you sit.

The man is more to blame, because the woman may be in such a hurry that she doesn't really have time to check.

Honestly, I cant point the finger at either. It depends on the relationship and the unwritten rules. In general though, both. As stated above.

@Faithgurl Ever think that the man is also in too big a hurry and forget to put the lid down? Double-standards!

Personal responsibility.

I think they're both to blame but I'm more inclined to feel sorry for the woman because she was the one who fell into the toilet.

Yah.

Who doesn't check the seat before they sit down? I've had times when I really needed to take a dump and I check all the time. There should be absolutely have no rules for putting seats down.
Though, I do put the cover and everything down. Not because of women, but because I don't want the water and germs spreading all over the place. Whether that works or not, eh.