One member did very violently attack a police officer:

> A police sergeant was left unable to drive, shower or dress herself after a Palestine Action activist allegedly hit her with a sledgehammer during a break-in at an Israeli defence firm's UK site, a trial has heard.

https://www.bbc.co.uk/news/articles/c4g54g1r15eo

Of course, one violent member does not make an organisation into a terrorist organisation. But, just as a matter of fact, there has been some actual violence against a person.