Have you guys met cheater like this?

In a game, I met a super strange situation. I was the top laner. This actually happened twice. That I am pretty sure, I right clicked the enemy champion, and then the auto attack order turns into a stop order. My character was supposed to AA the enemy champion, but it stopped just like I pressed the S button which I didn't. Both happened when there were only me and the enemy top laner dueling, so the other 8 players probably didn't see it. Even my teammates don't trust me. I believe it is something that he can turn it on/off. When junglers are top, this never happened. This only happened twice. Does anyone have the similar experience? This is pretty bad cheating.