This I absolutely agree with, but at top level sport, it has to be about rules. I wonder if the Bettina Hoy case was in the GJ’s minds as their freshest memory of what happens with a SJ timing problem.
In this case, I don’t think the rules were followed by the GJ (competitor did not salute prior to bell being rung).
For all the people saying she should have looked at the Jumbotron: I doubt the rules say that the official time is the Jumbotron time. I certainly wouldn’t rely on that as the actual timer.
When I walk my SJ course I try to ask an official where the judge is. It’s often not obvious at all. I prefer to make eye contact if possible.
If you watch top level SJ, they always get their horse in the ring, look at a fence, stop, let their horse poop (for which they put up a hand so that the judge waits to ring the bell) and/or back up before they start. There’s no doubt about hearing the bell.