You're right, it is bad manners, but the fact that it didn't happen with the other men on stage suggests it's more than that. Watch the video and see for yourself.
https://www.youtube.com/watch?v=Er7qPv8jsZo
You'll find that the moderator is much more willing to let the men speak throughout this conversation, whereas Hubeny tries to get a word in, succeeds, and then gets interrupted by Holt.
https://youtu.be/Er7qPv8jsZo?t=27m9s
So I think you're looking for grounds for sexism accusation which aren't really there.
Further more, there's nothing stopping her from stepping in and giving her views at any point, as other members of the panel were doing from time to time. If she's too shy to jump in, please don't blame that on the conduct of the other participants.
My advice: don't.
Listen.
Everyone has the right to express frustration, I think.
This thread is specifically and pointedly about men speaking over top women, especially when there is a power differential (panelist vs. moderator in this case). Not about the general problem of needing to speak up for yourself.
Curious, what did you think her original point was?
Yes, sexism/racism/classism/etc all exist and are all problems, but that doesn't mean every unfortunate circumstance is an instance of it. When you believe someone is wrong, it's (generally) not a bad thing to try to explain why you believe they're wrong. You may not convince them, but that doesn't make you a bad person (as long as you're willing to listen/try to understand) when they do likewise.
That being said, the circumstances described in the do appear to show sexism. I enjoyed the read.
> Why is it not sexism?
I feel like maybe you didn't actually read what I said, since what I said was that it did appear to show sexism.
The first paragraph of my response was addressing the person that said (effectively) that you should never disagree with a feminist about what is or isn't sexism (which is what I disagreed with).