Originally Posted by Often1

What makes you say that the delay wasn't WX-related?

That's the most common reason for crew delays. They're on a flight from XXX-SAN and it's late. Therefore, they aren't at SAN and the SAN-EWR flight is delayed.

As to compensation, you will have to talk with SK if you are thinking of EU-style compensation. UA will never, ever, ever pay out EU nanny compensation for a delay on a domestic flight, without a US court order. Start down that path and it would owe 10's of millions to people who had flown to a US gateway and missed an EU connection.