If Messi posted it it would be far worse given there would be a much lower presumption of ignorance given the nationalities involved, in my opinion. But Messi didn’t post this. I don’t know why I’m engaging this hypothetical since it’s you making this a “Messi v Ronaldo” discussion.
I can’t read into Linekar’s head, you’re the expert at that, but perhaps he thought the photo should be taken down (it really, really should) and reacted quickly and emotionally to seeing it? Perhaps he thought if he did it would be taken down? Or maybe just “this will help Messi win the meme wars against Ronaldo.”
You have to assume Ronaldo or whoever on his PR team posted that photo didn’t know what had happened when they did so, just by basic human standards of decency. Then again, it’s still up 18 hours later, which is even worse than posting it-probably unaware- in the first place.