The guy had a phone app out and opened he was using to scan their communication frequency, you can see him waiving the phone near the radio on their belt.
Did you catch the final seconds of the video? The guy recording was an NPR film and sound crew, it was nothing but a set up. The cop nudged him below the center of gravity of his mid section, no where near his chest. If it were enough force to send him reeling back, he would fell on his Ass not his head. He stumbled back to make a dramatic fall because it wasn't enough force, which caused him to trip over his own antics.
Now Trump is going to use the Media to trash talk OAN for the next few days, and they will. All the while putting OAN's name out there to every American. After every Hollywood Celeb and every Late night talk show, and every TDS cable news talking head has riddiculed Trump and OAN.
William Barr will come out and give a press conference, that the Old Bastard was supplying intel to Antifa to listen on the operations radio frequency.
OAN will be the most trusted name in news after that.
https://www.breitbart.com/politics/2020/06/09/trump-unleashes-twitter-attack-on-elderly-man-injured-by-police-at-buffalo-protest/