Anime watched it yet? Don't you think it's silly how the 2nd power of the world, Order of Black Knight, turned against their leader Zero by mere "supposed" facts from their dearest enemy of all time?
Brit - Zero has the power of geass which forcefully make people obey him.
Prove - None...
Brit - He might have used on all of us...
Prove - I suspect these people have been... *show papers*
Brit - He's a prince of Brit
OBK - But that doesnt matter no? He fight against Brit.
Brit - but he's a brit!
OBK - DAMN HIM!!!
Brit - He killed a lot of japanese and used you guys
Prove - He has geass power, he commanded the princess to do it. *play a tape*
OBK - OMFG!!!
Well being one of the leader of such big power, you'll think differently no? You'll doubt if those "proofs" are indeed facts since it came from the leader of the opposing force. Zero is the leader of OBK and without him, they probably wont even stand a chance against Britannia. Just because your enemy showed some supposed proof, which their credibility can be doubted, you dont necessarily want to kill Zero. it was too one sided and illogical except Diethard. Also, why wouldnt they doubt Oughi also? He was shown to have a relation with Villeta, a britinnia officer?