Yes...rules can be broken...for specific reasons carried out to bring a specific creative result...it's not just that you have a rule and it doesn't matter whether anyone pays attention to it or not...the rules exist because certain arrangements and techniques yield certain results and are pleasing to our eye.

If the OP broke this particular rule for some specific creative effect then I could see this phrase being used but it was an accident.

The comment about rules is valid, however, one must understand the rules before they can be successfully broken. Anyone can break a rule but it will generally be broken in a good way, if you first fully understand the rule. It usually does not work, nor is it a good idea to just go around breaking the rules if you don't first undertand them, because someone said you should, so please bear that in mind.

It is more likely to come from an habitual rule breaker, who just likes to break rules, when a statement reads "rules are meant to be broken". A more informed person might say something like "rules are there for a reason, and once you understnad them properly, then and only then can you successfully break them from time to time to improve upon an image. No disrespect meant to anyone on this list, by the way, so no need to come screaming back with all sorts or responses.

Yours is a very good photo with very good composition and yes the eye is led into the photos by the tongue on the bottom left. Your eye is, however, then led out again because the tongue extends back out of the frame. And that is why this is a very good photo, but if you had included it fully inside the frame, it would have been a great photo with great composition, and there lies the difference.

Had you taken both versions, you would have seen that the image with the entire tongue inside the frame would have been more pleasing to you than the image with the tongue end missing outside of the frame.

As stated, take what feels right to you at the time, then stop and rethink or relook at the scene, through the view finder. Explore the scene with your eye, look all around the viewfinder and see if there is anything you feel could be added to get a better feel.

Try zooming out a little or stepping a few steps back or panning slightly right or left, or switching to an upright format rather than a view/landscape format. That way you get to see if your subject lends itself better to one or the other of those different view formats.

When you have the time, as in this still life, so to speak, use that time to explore all avenues of composition and angle and then you can go home and see what really feels best to the eye/brain of all those different images you took.

As for the eye always being led into the photo from bottom left, as stated by Nikron, this is not true for everyone. This is only valid for westerners and why you may ask? Because we read from left to right and that is why it feels right for us. If we were orientals or middle easterners we would be reading right to left and this photo would not feel right to us and would have been better if the tongue were on the right side, leading us into the photo's main part on the left.

In general, and again this is a rule that once it is understood, can in certain cases be broken, you should always leave negative space to the right of a head shot (if you were to leave any negative space that is) and generally have the person looking or facing somehwat to the right, rather than to the left, in a western world image. The opposite applies for the eastern world.

So to recap, the advice you have heard is, for the most part quite correct. It is always better not to have something sticking out past your frame, if it is part of the main image and if it can be avoided. In your image you could have been a little tiny bit farther away and still had the buildings in the frame, along with the whole tongue of the wagon. Hope this helps.