Seems you're correct, here's what he had to say about it:
"I knew I was going to get a penalty. I'm not surprised," explained Hamilton. "I was in with the stewards, so I anticipated it. I always try to assume the worst-case scenario. It's only one spot, and it's not really made me feel any worse than how the weekend has gone anyway."
Asked whether he felt it was fair, Hamilton said: "It's racing. I'm not going to argue or disagree with the penalty."
"From my side I'm not allowed to move more than once. Do I class it as dangerous? No, but that's the rule. Twenty seconds is not such a bad penalty for it. As for Fernando, he hit me, he got a 20-second penalty, but it didn't really do anything to him. It doesn't exactly work out as a penalty, but again, that's racing."