In KMC peeps consider all possibilities and choose the best one, like if it is possible for Dante to stop time within a split second and hack something, then it is taken into consideration, so because he did not do it at one particular instant means nothing except that he didn't use the ability at that point. Dante and Vincent can both stop time (in Vincent's case it's with materia), so I shouldn't be reading Dante wins because he can stop time.
can he actually "stop" time and not slow it, in gameplay, in all the descriptions as well, its simply time lag, as well as the moves name "quicksilver" which would mean hes simply going faster than usual which is why enemies are slowed, the only thing that contradicts these 3 sources is the one video clip of him stopping some rocks, it seems however he takes a second of concentration to do it as well as it having a timer on it like DT has