Imagine a situation: a xenos breed is confirmed to stay on a large spacecraft, amongst thousands of unsuspecting passengers. The Inquisitor knows, however, that this xenos could easily plant his, say, eggs into the bodies of humans without them knowing it. Basically, this means, that this xenos is suspected to contaminate the passengers, but only a few of them.
And the Inquisitor orders to destroy the whole ship in order to bring down the xenos and his possible contaminated victims.
I would say this is Radicalism, and my reason for that is in this case the Inquisitor acts in accordance with the "The end justifies the means" proverb, thus "crossing the line" by slaughtering the flock he is actually sworn to safekeep.
Do you think it's Radical?