That's a good point about the Devourer Golem having takeout, though I think the devourer would have moved on in the couple minutes it takes for the Raid Engine to hit. I don't actually know what happened because I think the wave actually came from the opposite direction as the golem (the golem went "north" and the wave came from the "south" I believe), but I haven't scouted out far enough to know for sure.
Here's an interesting challenge for people who like doing that kind of stuff: play against two Raid Engine AI types, build a couple sets of Spirecraft Scouts, and send them all out on Auto-Scout at the same time. See if you can survive the AI response!