If they deem you a 'terrorist', any rights you thought you had disappear, which seems to be what they were threatening in this case due to whatever recent authoritarian laws they've introduced. Section 3 of the 2019 border code according to Max Blumenthal. Whether or not this could've applied to Klarenberg (apparently it just pertains to N.Ireland) I'm not sure but 'No comment' can only get you so far if they decide to really go after you. Still, my natural instinct too would've been to keep my mouth shut.