AN - yes I guess so, the idea being that if it's not such a horrendous thing that you don't feel you could continue with the employment relationship, then it's not bad enough to dismiss summarily without notice.
So you could argue that it's not in the employer's interest to attempt to deal with it, but the argument would be that if continuing is an option, the act wasn't gross misconduct in the first place iyswim?
I would agree that in retrospect this relationship had broken down already. I think helpwithnanny dithered a bit during the whole episode which effectively ruled out summary dismissal without notice as an option for her, although it definitely would have been an option had she suspended the nanny after (for example) the 'get a life' comment, and then dismissed her.
Although this nanny had less than a year service and therefore no right to claim unfair dismissal, she does have a right to claim wrongful dismissal, which is not much, but relates to things like non payment of notice. So if helpwithnanny dismissed her without notice for something which hadn't been considered that serious previously, what she could have done is sued for wrongful dismissal as withholding notice was not fair in those circumstances.
Whether she would have actually done so is obviously another matter, and there would be no 'punishment' of the employer in those circumstances other than being forced to pay the notice. So an employer could take the risk in those circumstances and make a judgement whether there were likely to be any repercussions (legal or otherwise).
Helpwithnanny was keen to be legal and fair, and at the point she was at at the beginning of this thread, I would have said dismissal immediately with payment in lieu of notice would have been the 'right' and fair thing to do.
However given the circumstances in which the nanny actually left, obviously no notice pay need be paid and I think witholding money to cover items stolen and damage done would absolutely be reasonable as well.
Sorry for essay!