I agree w/ some commentators who said that it was holding, but also a good no-call.
If Kaep had made a better throw, there would be more of a gripe. But you don't reward a bad throw & a bad play w/ a Superbowl win. It would have been much more controversial as a call than as a no-call.
I will never understand the bold. Ever. If it was holding (and it was), it should have been called. You can't have a good no-call on an actual penalty. If it had been called, there are few people outside of Maryland that would have argued against it.