Unless there was clear unequivical instruction from air traffic controll to stop and turn there..."cleared for takeoff"
"comence takeoff run at your discretion", etc, then it's a Pilot....former pilot error.
In any case it took at least three people getting it all wrong before someone hit the brakes, recordings are going to be classic, "not like this" education material.
The aircraft reached 107kt on the taxiway.
V1 (the "point of no return" where a takeoff should not be aborted) for an A320 is around 120kt to 145kt.
Which is a metric that assumes a certain length of runway infront of you, not a taxiway.
Well what is the maximum speed to reject a takeoff on a taxiway?