Sorry but there is not enough evidence in this demo to warrant a ban. I will compile a list of reasons below.
1. The demo is 5 seconds long.
2. The demo is useless and bugged for the first round - so we don't see who or how he is shooting someone.
Please try to begin your demos at the end of a round (just before the new round is about to begin). This will fix any issues with invisible players and bugged demos. As most demos are bugged if the demo begins during a round. We are unable to see players during that first round, until they are killed.