...it is far more dignified to admit you're wrong than:
(a) to go silent or change the subject;
(b) to keep on arguing so as to appear consistent?
I see this countless times on MN and in RL and it always makes me rofl! A friend who normally defaults to option (b) (huge ego, bless) was once in this position and willingly made the BIGGEST climb-down I have ever seen. I was because he's the last person I'd ever think would admit he was wrong, but it left me with so much more respect for him than I'd had until then.