I did not see this race live, but after looking at the replay, I'd say that the stewards' decision is what I would have guessed. Fouls around the turn seem like they are less likely to be penalized, and the cost-a-placing rule usually requires a closer finish than occurred here.

Your post caused me to think back on a thread that TGJB started a few months ago:

https://www.thorograph.com/phorum/read.php?1,110012,110012#msg-110012

In my mind, the cost-a-placing rule as currently enforced makes little sense. I think most people who post here enjoy the intellectual challenge of the game, and it's frustrating when you make what appears to be a winning bet, only to have your horse taken down because of a foul that did not affect your horse's placing.

I like the international rule that your horse gets taken down only when the foul enabled it to beat the fouled horse. When the foul causes the victim to lose a placing, that should be dealt with via purse money, and, rather then moving other horses up, purse money should be redistributed directly from the perpetrator to the victim. A draconian approach would be to have the horses swap purse money. A less severe approach (but one requiring more judgment on the part of the stewards) would be to have the perpetrator compensate the victim for purse money lost as a result of the foul.