I'm pro-Palestine, but Palestine Action seem pretty dodgy. Between attacking RAF planes (which are most likely used in Ukraine, not Israel) and attacking a manufacturer in Europe that allegedly sells to Israel (destroying equipment bound for Ukraine), the things they do seem to have merely a veil of pro-Palestine while ultimately benefitting Russia. At the very least, I have a real concern that the group has been infiltrated and is influenced by Russia.
I do think they've twisted the law somewhat to find something it fits into, but feel that action absolutely needed to be taken against the group. Mainly though this is because "terrorism" is defined as "using violence (or the threat of violence) against civilians in pursuit of a political goal". Their actions have been against military, not civilians, and thus cannot be terrorism. But treating them as a military threat would be twisted and presented as an even more inappropriate response, even though that's what they are.
Edit: Lmaooooo all the lemmygrad and hexbear users came out the woodwork, right on cue. As soon as you mention something Russia isn't doing...