I would like to know this history, because the only thing I can truly think of was the Varitek/A-Rod fight in 2004. And, well, I don't blame him one bit for that. Other than that, I can't really think of anything. I can see Varitek just trying to tell him it wasn't intentional and Kinsler being real hot and reacting sharply. That's probably what happened. Varitek wasn't angry until after Kinsler barked at him. Whatever, it doesn't matter.
No, he wasn't hit in the head intentionally. It made no sense whatsoever from the situation at hand, and Cabrera has poor control and was trying to back Kinsler off the plate but it got away from him. Unfortunate, but unintentional. No one sends a message by hitting someone else in the head unless he's a known headhunter.