Why are street protestors exempt from the corona clause?

It is nearly four years since Black Lives Matter had their first major protest in London. Emulating their US counterparts, the protestors held up their hands and chanted ‘Hands up, don’t shoot’, a chant popularised after the 2014 killing of Michael Brown in Ferguson, Missouri. By then it had been known for a year that before his death Brown almost certainly said no such thing and had lunged for the arresting officer’s gun before being shot.

Still the London protestors chanted what they believed Michael Brown had said, as they processed along Oxford Street, accompanied by unarmed British policemen who couldn’t have shot them if they’d wanted to.

Two weeks later a crowd gathered in Hyde Park chanting ‘Hands up, don’t shoot’ and other BLM slogans. By the end of the evening a police officer had been stabbed, four other PCs had been injured and a young man chased into the middle of one of London’s busiest streets and set upon by three men wielding a machete.