>>802653
It's been around for a few decades, and all theories are predicated on assuming the matter is simply moving at less than the speed of light and working backwards using special relativity and making assumptions about beam orientation based on that, with less consideration on the visible information.
It's handwaved away by postulation that the beams are simply heading in a different direction while still appearing parallel to the observing device (angled towards or away from the observer), and people suggest that we're seeing the matter's transverse velocity, discounting the observed information.
So scientists wish to suggest that matter is heading diagonally away (or towards) from us, and so it appears to be moving faster as a result. This of course is plausible, but one would counter that this cannot be the case 100% of the time, and also that it surely would have been reflected in the raw data first, which it wasn't.
>>802662
It's an example of scientific conservatism. People gesture to special relativity and discount visual data.