The fact that the bullets aren't aimed at the opponent exactly is an artifact of the replay system, nothing unusual to see here.
If you check demo footage of other Source FPS games this common across each game.
However the tracking is really unnatural, I am leaning towards this being an aimbot, however the only way to decipher this further would be by uploading the demo file here, or recording the fullspeed at a much higher FPS to try and understand the mouse tracking "shape". Then decide if a person could have actually performed those actions.
In the clip, she fires 27 shots, but there are 24 ticks of damage. This means an accuracy of 89% against a charging warden. That doesn't seem legitimate to me, even the best Quake players in the world don't achieve >40% accuracy with the Lightening Gun.
Edit: The 2nd clip in the base looks like either a very lucky shot, wallhack, or trigger bot. I would be interested to see it in full speed to gague the reaction time required to make that shot, it appears that the time between warden being visible and the shot being aimed and taken is very small, if it's <0.2s it's a good indicator that it's not legitimate.