8:30 on the second demo is definitely a speedhack. 7:59 too.
7:03
2:45
1:27 looks like a wh
1:15
0:50
0:34
0:08-0:06 speed and wh
Did you have voice recon during this match?
Will edit the post when I watch the first demo.
EDIT: around 17:30 - it really does seem that his hardware or internet lag is causing changes in his speed.
And yeah, the speed-ups happen on random occasions, even when he's not alive. It's like the game itself is trying to sync back or something. It happens all the time in RTS', but as far as I know, it doesnt happen in FPS'.