All of this is just my opinion.
The general rule of civil (as opposed to criminal) law is that you have a trial when there are "genuine issues of material fact which preclude judgment as a matter of law for one side."
In this case, the judge at issue has to decide whether the disc jockey has the right to get a jury to reach a verdict on whether he was "defamed" when Taylor Swift said he grabbed her ass (her allegations resulting in him being fired).
At this point in the case, based upon what has been reported (see above link), I really fail to see how the case reaches the jury. Again, according to reports:
1) The DJ testified that he "may have" had some contact with Ms. Swift's ribcage area, but never grabbed her ass.
This self-serving testimony is the ONLY shred of evidence that has been presented in his favor.
Against this allegation, there is an actual picture of him reaching toward the bottom of her skirt with his hand and appearing to (at the very least) fondle her below the belt. So, his testimony cannot be believed. He has lied about his hand placement and his story in my opinion,.is, simply put, false.
Against this tale, which has no credibility, you have Swift testifying that he grabbed her bare ass under her skirt and that she immediately shimmied away toward his girlfriend (which the picture also shows). You have two different people testifying that they witnessed the DJ grab her ass and others testifying that she told them immediately thereafter that the DJ had, in fact, grabbed her ass.
How is there any genuine fact dispute here? Can Kyrie Irving sue a school district for teaching that the earth is round and reach trial by testifying "I think it is flat"? I mean, at SOME point the judge has to step in and stop the charade. In my opinion, he should have awarded summary judgment against the DJ and given Ms. Swift her $1 in damages she was seeking.
That said, there are judges who believe that they will try to let the jury "do the right thing" and then intervene only after the jury has made a grotesque error. While this is the safer play in many cases (i.e., cases that are halfway close), this sort of decision creates situations where people have to go through a jury trial and pay a lawyer $1,000,000 to defend ridiculous allegations.