Scott,
     I've seen 2 variations in logs of what you've experienced.

(1) In the multi-cache on South Mountain (something to do with balls),
there are I think 2 find logs in which the person only did part of the
multi-cache.  One stated that it got dark and couldn't finish.  The
other stated not finding one of the stages but reasoned that since
everyone else had problems that he/she couldn't be expected to find that
stage.  (There's no evidence in prior logs that anyone had trouble with
that stage.)

(2) I saw a couple of logs on caches in the San Diego area where someone
went to the coordinates of a regular cache, didn't find the cache, and
logged it as a find reasoning that (a) they went to the right
coordinates and (b) they gave it their best effort.

If either the above 2 find logs appeared on one of my caches, I'd (a)
email the person to explain that I don't consider their find a find and
(b) delete the logs.

My understanding is that the purpose is to find the cache, not go stand
on the coordinates stated on the cache description.

-srdrake