Yep. The one potential counter move would to be going full Chinese propaganda and just flat out deny deny deny that they are throwing rocks or doing anything remotely violent at all in the first place. Even though there are videos, you make the lie big enough and repeat enough times and the masses will believe it. I've seen a few reddit comments taking this tack out in the salt mines but luckily even in the leftists nests of worldnews and news the replies providing the video are getting upvoted and the comments denying it are being downvoted. So it seems the hivemind at large missed the window of opportunity on that plan of attack and will be stuck defending rock throwers exactly as the president anticipated (in my opinion at least).