Switch roles here. If you were the interviewer ranking candidates, and you had someone who did not follow instructions and showed up late, would you have a concern that the candidate would have difficulty with these same traits in residency?
I would tend to interpret similarly to Eigen. I would learn from it and closely follow instructions in the future.
As a DI used to say:
When you are early, you are on time
When you are on time, you are late
When you are late, you or your team are dead
Forward to today many years later, I still hear his voice in my head and consider this sage advice....
Wook