A shadow to indicate line of play - does intent matter?

Another hypothetical that would almost certainly never occur, but, hey, it's still fun to learn, right?

The situation:

Playing a leisurely early evening round with my 6 year old last night and I arrived at my ball in the fairway of the 11th hole and parked the cart to the west of the ball ... without really thinking about it.  (With a 6-year old in tow you're paying attention to a lot of non-golf related things ;))

When I start to line up my approach shot I realize that I've put the cart shadow in front of my ball.  I like to use an intermediate target when lining up shots as well, and you can imagine that this shadow helped me with that.  I was most definitely not thinking about that when I parked the cart, so the question becomes: Is playing a shot with the cart there, and the shadow assisting in getting the line, a violation?

The rule (8-2) states: Except on the putting green , a player may have the line of play indicated to him by anyone, but no one may be positioned by the player on or close to the line or an extension of the line beyond the hole while the stroke is being made. Any mark placed by the player or with his knowledge to indicate the line must be removed before the stroke is made.

The second sentence is where it's at, I believe.  I would argue that the carts' shadow would certainly qualify as "any mark placed by the player."  The question involves the next portion of the sentence - "to indicate the line."  In this case, the mark was not placed to indicate the line, it just so happened that it did.  So does the intent when placing the mark matter?

I also glanced through the Decisions, but didn't find any that pertained.

There are several cases where indicating line of play inadvertently is not a violation.  For instance, if a caddy removes the pin and inadvertently stands with his foot on a direct extension of the putting line, that's not a violation - as long as there was no intent and it was truly inadvertent.

Or if your partner was ahead of you and placed his bag on the hill and happened to put it right along your line of play, it would not be a violation unless it was done on purpose to indicate the line of play to you.

So no, accidentally parking your cart where the shadow happens to coincide with line of play would not be a violation.

I'd say that intent certainly matters, by the explanation in the rule itself.  If you purposely parked the cart there with the intent for the shadow to indicate a line of play, then IMO you'd be in violation of the rule.  If there was no such intent and it just happened to turn out that way, then I'd say there's no violation - no different than using a divot mark, weed sprout, dry patch, etc. ahead of your ball as an intermediate target to line up your shot.