Some monsters (like Medusa) become horrifying when you Disarm them, because in the case of Medusa, her Wrestling skill is much higher than her Archery, and her Base Damage is a lot higher than her Bow's Base Damage.
When i first read the title, i thought this was going to be about how annoying it is that the Allosaurus can Disarm the player. Which is essentially an anti-Sampire tactic, same as the Gorillas throwing 20+ damage Bananas at anyone that hits them with range or AoE (specifically Hit Area weps).