I think you've got to cut people a bit of slack in their second language tbh, particularly with memes. There are cultural references and subtext that foreigners sometimes simply won't get, and certainly won't know if they're offensive. He's pretty good at English, but to be honest I've taught Masters degree students at UK universities who could have trouble with this kind of thing, particularly if it's posted as a quick retweet without really thinking about it. There are huge corporations with highly-paid PR departments regularly fucking up in Asia as we speak because they don't know what's considered offensive over there, and here we are talking about some kid who plays football for a living.