How to accredit waiting to enter a meeting?

In Chile, Zoom is used for court hearings.
The point is that a court official is the one who gives access to the meeting, sometimes, and you have to wait until that happens.
It happened to me once that the official did not give me access until late in the meeting, and the judge told me that I was the one who had arrived late. If that happens to me again, how can I prove that I was in the waiting room from the time of the meeting appointment and that it was the official who delayed letting me in? Stay tuned.