"President Castro, I think,"
That's the first 4 words of the Obama quote.

That's diplomacy, the art of dealing with people in a sensitive and effective way. I don't see it as weakness or bowing down to anyone. By choosing the words "I think" he can change or twist Castro's words anyway he wants if that works for our position. If the other person says he got it wrong there is no loss of face on either side.