I am aware that the person hoiked away was in Scotland. However I think the following link is of interest
https://www.cps.gov.uk/legal-guidance/offences-during-protests-demonstrations-or-campaigns
In Munim Abdul v DPP [2011] EWHC 247 (Admin), the court held that when considering the interaction between the section 5 offence and Article 10, the following principles apply:
The starting point is the importance of the right to freedom of expression.
In this regard, it must be recognised that legitimate protest can be offensive at least to some – and on occasions must be, if it is to have impact. Moreover, the right to freedom of expression would be unacceptably devalued if it did no more than protect those holding popular, mainstream views; it must plainly extend beyond that so that minority views can be freely expressed, even if distasteful.
There is more…