You did but only after being asked for your railcard presumably?
You must have a valid ticket for travel before stepping onto the train to start your journey, in your specific case, you don’t have a valid ticket at the time your journey began. If you would have renewed your railcard before stepping onto the train, you wouldn’t have been travelling on an invalid ticket and therefore not reported by the revenue officer.
I notice earlier on that you were wondering why you had not been issued with an on-the-spot £50 penalty fare and had been issued with a Ticket Irregularity Report (TIR). The usual reason for this is that with an expired railcard, the railway companies check your previous booking history to ensure you haven’t previously travelled with an out of date rail card on previous journeys (therefore travelling on invalid tickets) on or after the point at which the railcard expired, this is the correct procedure.