Between minutes 1:10 and 2:40 Derek from Veritasium describes how the magnetic field transforms in electric field if you change the frame of refference. But let's suppose that his "positively charged cat" moves near the wire with a non-relativistic speed. If this would be the case , then we could say that the charge densities stay the same in the refference frame of the cat since the distances between the charges didn't change significantly. So the electric field would be 0, and so the cat shouldn't move ( but this would contradict the behaviour in the 2 frames).