The real question is where the 4 quarts of oil went. Yes, your user manual says to check the fluids every ... I think mine says 8 hours for the first 24 hours. But even if you had checked it, the kind of issue that causes you to lose 4 quarts might have bit you even if you started with the reservoir full. Although you feel bad about this incident, don't be too contrite with the dealer. If you walk in there and say, "I screwed up my tractor. Sorry about that," he's going to say, "Yes, you did. It's no problem. Here's the bill." Tell him the facts: I last checked the oil at this time, and by this time, 4 quarts was gone. Don't do him any favors by volunteering information about what you should have or could have done. Focus on the fact that your tractor had a dramatic loss of oil and what the underlying cause of that was. In other words, try to keep the focus on what the dealer legitimately might be responsible for, instead of drawing the focus onto what you might be responsible for.