It pretty much looks like the player is using a macro tool, either a software like autohotkey or, more likely, some programmable input device like a gamer keyboard. Nothing special actually.

It is of course possible to do all this "bare-handed" if you´re quick, but its a real hassle.

One thing to note is that this type of playing is very hard to do effectively unless your game runs very smooth. In my own testing, I have problems with it simply because my ping is too high due to being half a world away from the physical servers in Massachusetts.