Some more context from the Head Coach today:

"As painful as it has been dealing with Coach Gundy resigning
from the program, it doesn't touch the experience of pain felt by
a room full of young men I am charged to protect, lead and love.
There are a few things I would like to address.
Coach Gundy resigned from the program because he knows what
he did was wrong. He chose to read aloud to his players, not once
but multiple times, a racially charged word that is objectionable
to everyone, and does not reflect the attitude and values of our
university or our football program. This is not acceptable. Period
Coach Gundy did the right thing in resigning. He knows our goals
for excellence and that coaches have special responsibilities to
set an example. He also knows that, while he will always be a part
of the OU family, that his words affected many of us and did not
represent the principles of our university. Again, his resignation
was the right thing to do, and we will move forward positively."

Sounds like Coach Gundy thought he did wrong and owned up to it. Resigned and BV agreed it was the right thing to do.