If you rearrange this event:
...then it works as intended.
So what's happening is that in the first example, the fast loop breaks the scope of the event. So when Fusion returns from the fastloop back to this event and change animation direction action fires, it has no scope. So it can't fire on the clicked active because it no longer knows which was clicked. Since it no longer knows which was clicked, it has to choose the active some other, more arbitrary, way. So it uses the time of creation instead. It fires on the most recently created active instead (you can confirm this by making more duplicates - the last duplicate you created will be the one to go red). So far, that all seems reasonable and logical to me, actually.
The thing that I think is weird is not that it fires on the wrong active per se, but that it still only fires on one active. If the scope is broken, shouldn't it change direction on all actives?
I found similar oddities when I wrote my scoping article a while back. I'll point out some more idiosyncracies:
Like I said, fusion is applying the change direction action to the most recently created active. So, if you create a new active in that fastloop, that will be the most recently created active, and it will become red:
Interestingly, this actually applies to multiple actives if you create more than one in that fastloop:
But then add in another action into the fastloop before the creation events, and it goes back to affecting only one: