1) goto 0:50 on clip
2) click on "setting" and then "speed" to slowdown to .25 speed
3)View 0:50-0:52 segment to see puff of smoke ejecting at high speed from perp's hand
4) Repeat step 3, till your blind anti-cop passes and you can see the truth
What apeared to be smoke at 0:51-0:52 is - when viewing the clip past this point - actually some sort of reflection on the camera lense or out-of-focus material waving in the top left of the video-picture.
Apologies for the misinformation.