He maybe playing on a mod. We used to wonder what the hell these things were for.. a long long time. Sometimes people would question them... and there is only ob with pmove_fixed, so I used to refer to these things as the "wtf's". I would often see someone type 'wtf' and I cound guess what section of the map he was at.
I find the air strafe very difficult, never did get the hang of cpm.
There used to be some demos on spirits site, you might need to clicky around - or view the flash steams
herehttp://dfsp.sp1r1t.org/i thought they were inactive, i need to check this airrocket thing