I hate this kind of thing. We have a data set of zero when it comes to alien technology. It is an unknown, unknown. The speculation is fun, but about as relevant to reality as “would we recognize fairy magic if we saw it?”

Would We Recognize Extraterrestrial Technology If We Saw It?

It depends on what kind of technology it’d be.

Fire is technology. A hammer is a piece of technology. Plenty of examples of alien technology would be easy to recognize as such, even if we wouldn’t have the idea about its purpose. Especially now, when so many SF stories, movies and video games had provided us with great many deal of examples of weird, alien stuff.

That author has a very narrow mind.

It drives me nuts when people act like humans have figured out everything there is to know in the universe, when we in fact haven’t even discovered everything on our own planet.

We can tell where in the Sol system a meteorite is from, based on no technological residue at all. And we can tell where something has been constructed on Earth by analyzing it, because of what it picks up from the environment in the process, so I assume it would be obvious when something had been made by an alien civilization in an alien star system on an alien world.