My opinion is that's too fast to be anybody's trigger finger, short of Flash Gordon.

It looks like - but it's hard to tell from a video with any certainty.  One thing guys with modded crontrollers will do is put a silencer on the weapon to hide the rate of fire.  The other "tell" is how well they mantainin consistency with the rates of fire.  I'm pretty fast, but there's always a delay or slipped finger or ryhthm change.

If you suspect them - mute, avoid, block and report - then forget about them.

I would say that's a yes unless you were playing against Clark Kent.