I've seen the video, and I do agree with @Kramer.
It could be just an extreme lag with desync that may have caused that. Another thing I'd like to point out is that the player took some time there to kill you when you were knocked down with stubby which makes me think that the player ping was very high or spiking to see the "fall animation" play out on his screen about a few hundreds ms later. On the other hand it could be the player using something like you've stated in your post "lag tool", however I still wouldn't be able to do anything since there is no solid evidence that the player is running the so called tool in the background to gain that advantage over other players. Also the main question in here is : "Does that lag tool even exist?"
If it does exist we need more details and solid evidence of the tool, otherwise we can't take any strict actions if we have no clue at all about this tool. Besides that we don't have control over players their PC to check what files/tools they're running which makes it almost impossible to detect a tool like that.
We'll keep an eye on the player anyway.
I'll lock the topic now. If any staff member would like to share his opinion feel free to unlock it.
~SuriAttacker
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