If there's a pattern of sloppy traders trying to fill large orders by splitting them across exchanges and firing them off at roughly the same time, then having seen a trade at one exchange and not yet at another, it might be a good guess that a trade was incoming, if I'm faster enough to make those decisions.
I don't really know if that is the case (or ever was).
Suppose there is a pattern of 10% of traders being sloppy, and 90% being not sloppy. If you run this strategy, you lose 90% of the time.
Additionally, whenever a small trader comes along, you are again overreacting. I.e., I make quite a few (automated) trades. I never cross exchanges or blow up more than 1 level. Whenever I trade you are again buying all the shares and probably losing money.
What I described as acausal is responding to an order at BATS before it gets there. Guessing that maybe an order might go to BATS because you saw one at ARCA isn't acausal.
I don't really know if that is the case (or ever was).
In any event, it's not acausal.