Scathan neutralized Protege while his attention was focused else where. Going by what we say in those panels it seems Scathan possesses the ability to shut down any being with a thumbs down. The next time we see Protege after he got the thumbs down, he was muzzled and handcuffed.
imo Scathan had the power to do what the situation required. We don't know how strong he is but he can disapprove of anything and will act to stop any threat.