Perhaps our observations are a result of existing within two gravitational space-time distortions, one trivial and one not. The trivial one being the Sun and the non-trivial being the galaxy which we inhabit.
If curvature of space-time theorized by General Relativity is accepted, then observing non-local energy will be affected by gravity in which the observation is being undertaken. Accounting for the Sun's influence has largely (if not completely) been addressed, but there lies a more difficult "elephant in the room" problem of determining what effect the gravitational curvature of the Milky Way has on any observations we can make.
According to the University of Oregon[1], the observable mass of the Milky Way is 200,000,000,000 Solar masses. The same material indicates that visible stars account for 30% of that. Throw in a bit for singularities and lets call it "less than 50%" for the sake of discussion. In any event, there exists enough mass in this galaxy to plausibly state that the space-time we inhabit is affected. Yet a non-trivial amount considered "unaccounted for."
Using the canonical 3d inverse-cone visualization of matter's effect on space-time, imagine our solar system exists on some point within the galaxy's gravitational cone yet not near its center. Making intra-galactic calculations may be influenced by compressed space-time instead of the presence of dark matter. And observations regarding other galaxies colliding (as mentioned in the article) migth be explained by gravitational phase shifting.
Though all of this likely will be rebuked, it is why I originally said "sure."
Sure.