I don't know if Alliston's defence made the case that shouting at pedestrians is often more effective and quicker than using a bell or horn. Also swerving on a bike can be an alternative to braking, if you are not going too fast. These points don't seem to have got through to the judge who referred to Alliston's shouting as proof of culpability.
IMO, trying to make others modify their behaviour (by shouting, ringing a bell or blasting a horn) is very rarely an effective way to avoid a collision. I base that on my own experiences on bicycles, motorbikes and in cars, on the road, on off road trails/pathways and on the velodrome.
If someone has put themself in your path either by not seeing you or by deciding they have more right to be there than you (and this has happened in all the vehicles and locations I listed above) I think it is much safer to leave them to their stupidity/arrogance and go about avoiding them.
I fully believe that if Alliston had kept his mouth shut on that day, Briggs would be alive and he'd still be skidding around London.