It takes a special kind of person to continue to proclaim their innocence so fervently even when presented with irrefutable proof that they’ve cheated.
Is it?
I'd say that everyone has the potential for this weird survivorship behavior where you can't admit the truth for yourself.
It's probably related to a deep rooted cognitive dissonance where it's less painful to keep maintaining your innocense than to admit the truth.
In the right environment (such as an ultra competitive one where your livelyhood is at stake) most people would rise to the occasion. Just as most people would be able to kill people in a war.
No? By denying it there's still a chance you'll get out of it, however tiny that chance is. That chance becomes zero when you admit it. A "shred of integrity" won't pay your trainers mortgage.
There's probably more recent ones too, this was posted here recently so was on my mind.