I feel sorry for Kyle, even though (I'm so sorry) I was desperate for Shapovalov to get through. But not like that. At least Shapovalov was magnanimous/thoughtful in his victory.
He was and also he had the grace to admit later that he hadn't been playing all that well, which is true, although he was becoming much less erratic during the second set as his nerves settled down.
Fortunately the injury doesn't sound serious. According to Kyle it was a muscle spasm that caused his neck and the top of his back to lock up, quite possibly because this was the 10th match he'd played in 14 days plus the tension of playing in a Slam, and that he hopes to be back on the Tour soon.