After reviewing the demo on sourcetv, in my personal opinion, this person was just lagging. Their lag at the suspected time was around 175-200 range, which could have created lag spikes for the player. I checked the cl_showpos, no velocity that passed 260, or if it did it went up to like 263 at most. Looking from Omegawiz first person spec, yes it seems like a weird speed hack (burst forward), but looking in LaurenIsHere first person spec, just lag spikes.
Demo is provided below, in my opinion, ban should be taken off. I provided the tick mark so clan members or ULA does not have to watch the whole damn thing.
Tick 34000 is the start of the round where LaurenIsHere is suspected of speed hacks, watching afterwards, no real suspicion of speed hack, just lag.
Tick 59000 is where the player gets banned. In between, nada.