There's just no excuse for that ! Not sure I would fly that one again at least until it has been for maintenance.
I'm lucky enough that I'm an early riser so all through my training I was 1st to fly - so I got into a habit of doing a full check everytime. Now I can't get out of the habit, it doesn't take that long.
You didn't mean really FULL did you ? There is a max quantity as well, any more and it spews out (I was told), but I'm sure you knew that.
Has your CFI taken any action ?