I think it's funny that you confuse 'true odds' with 'your odds'.

The coin flip actually has 'true odds', while your judgement is apparently so infallible and all seeing that your own odds become reality in judging a race.
Do you know what 'hubris' means?

To begin with, Spain was 3.7-1 ---- almost double the odds you cited.
Already, there's a knock on your judgement.
Secondly, the even money favorite was a stretch and should have been 6 or 8-1, that alone should give you a hint about Spain's 'true odds'.
The fact is, she was much the best, should have been favored, and you simply failed in handicapping the race.

Mall was convinced that no mare in foal could win a stakes, and apparently he was also dead wrong.
I guess Lukas won't be calling him for advice, after all.

Personally, I don't look for reasons to bet short priced horses, whether they're value or not.
Some people would jump on a 7/2 that should've been 2-1, but that's just not me.
The quality of the horse is obvious --- the quality of your judgement is not.

By the way, if she was 'third best' (according to you), who were the 2 horses more likely to win, and why?