It is difficult to ignore a distraction in a public setting where attention is surplus, scattered and variable. For one thing, collective 'ignoring' is more difficult to coordinate effectively.
I would even say, you could politely make the point that, while gratuitous offence should generally be avoided, the higher ideals of truth and freedom of speech should not be sacrificed in the name of avoiding offence. None of this ought to be abrasive - I would doubt the good faith of any individual who found such an argument itself offensive, I would tend to interpret it as a learned behaviour for winning arguments without actually having to put forward any reasoning.
I think there's a third option for dealing with the person in the audience: ignore her.
It is difficult to ignore a distraction in a public setting where attention is surplus, scattered and variable. For one thing, collective 'ignoring' is more difficult to coordinate effectively.
I would even say, you could politely make the point that, while gratuitous offence should generally be avoided, the higher ideals of truth and freedom of speech should not be sacrificed in the name of avoiding offence. None of this ought to be abrasive - I would doubt the good faith of any individual who found such an argument itself offensive, I would tend to interpret it as a learned behaviour for winning arguments without actually having to put forward any reasoning.