Do ask at the airport, they should be able to give you a confirmation note of delay including the reason.
They might want to say that the reason for delay is "Aircraft rotation, late arrival of aircraft from another flight or previous sector" (DLY93 in IATA code speak), in such case, ask them to please indicate the code received for late departure of inbound from Zurich. They should have it available via SITATEX or whichever system they use.