No, it's not. I can name a thousand reason why a person get into a raids and quit, and there is nothing you can do about it
There is no prove. Simply none

You can argue all you want. It can look very obvious to you, but as long as start a raids, drops a troop and end raids are not against ANY term and condition, there is nothing SC can do about it. And if SC ban people without them doing anything against the ToS, they will be in big trouble.
Heck, I hate my leaders, so I want to waste my attacks to send a message. Heck, I think I can defeat him, so I attack, then I change my mind. Heck, my son gets his hand on my ipad, and waste my attack on a base than I can't beat. Heck, I start the attack because I want to, and quit because I want to. Heck, my wife doesn't want me to do war, so she waste my attack. Heck, I drop 1 troops because my leader say so. I don't care why he wants it. I just do what he told me to do.
All I'm saying is... dropping 1 troops is far from violate ToS. Prove all you want, but all you prove is he doing exactly what ToS allow him to do.