Could the Chicxulub impact have been a relativistic kill vehicle?

This is something I just thought of. What if the Chicxulub impact was the result of an alien civilization a few hundred million light years away trying to eradicate life on Earth before it could pose a threat to them? Maybe this is why we don't see life anywhere else in the Milky Way and the weapon just happened to misfire when they used it on Earth. No asteroid fragments have ever been found from the Chicxulub impactor, only microtektites, which makes this theory plausible in my opinion.