After discovering that the nanny originally hired to look after George and Sibby blatantly hated Sibby because her father was an Irish chauffer, it suddenly makes everything she did earlier look much creepier. Her ordering Thomas to not talk to Sibby initially seemed like her being overprotective and his refusal to pass along the message to not give Sibby an egg with tea ("Why shouldn't she have an egg with her tea?") came across as his usual jerkishness, but it makes one wonder if the nanny had been trying to isolate the poor kid and begin starving her.
Could also be an example of Nice To Waiter being true. Someone being rude to their inferiors is a warning sign of their character, and it was not just "coincidence" Cora caught Nanny being mean; she was cruel all the time, and it showed in those red flags. Although Thomas was probably upset about being treated rudely by the Nanny on personal grounds, he also knows that is not how the Crawleys treat their inferiors and not the values they want being passed on to their kids.
It's likely both; Thomas doesn't like the way the nanny treats him largely because he doesn't appreciate being treated that way, and if she was polite and friendly he might not have bothered... but he's also historically been fond of Sybbie, and her nanny forbidding him from even talking to the child of a woman he respected would have made him furious for entirely different reasons. His tone when he asks indignantly why Little Sybil shouldn't have an egg just like George is very different from his usual manipulative politeness, which hints at him being genuinely protective.
Sybil had told Tom she wished she knew how to fix an engine. Its a clever way of her to express her need to be free. If only she knew how to drive and fix a car, she'd hop in and drive away from Downton and finally be free to be her own woman.
The TWoP thread for Downton mentioned how Robert and Cora lack parenting skills. This makes sense when you consider that the people that raised them wouldn't have been their parents, but rather a Nanny.
How exactly did the prosecutors know specifically which servants had been eavesdropping on Mr. Bates?
The prosecutor mentioned Mr. Bates gave reports to police. It's unlikely he'd have been anything other than honest and thorough. He likely mentioned that Mrs. Hughes and Miss O'Brien knew things about the situation.
Handing them that information, though, does seem to have put Bates into Too Dumb to Live territory-almost literally.
Referring to the quote on the main page ("we all have different parts,etc."): What a load of crock. If you don't have a need for someone, stop paying them and fire them. But later, when the Crawley family goes through yet more financial difficulty, it becomes clear that this "everyone is entitled to a job" mentality may have been causing this unstoppable decline.
Except that Robert firmly believes it's the duty of a lord to make sure his people are taken care of, i.e. employed. That's almost exactly what he says to Matthew regarding Molesly: yes, Matthew might find him superfluous, but getting rid of him would deprive Molesly of his livelihood.
Yes, but Matthew pretending he can't dress up on his own doesn't make much of a difference about Molesley's livelihood. Standing there idly may be frustrating, but Robert makes it sound like Matthew at least wants to throw him into a dungeon and starve him to death. Even assuming their house is his only chance to get a job, and he couldn't do anything really useful, like helping out in Downton Abbey where there is too much work to do, or in some charity action of Isobel's, or doing errands in Matthew's office. This was rather guilt-tripping Matthew into a lifestyle he was uncomfortable in. Not to mention not Matthew is the lord yet. Why would he have to do Robert's job? And if he has to take the responsibility, where is the power with it? Has he no say in reforming the system, changing the "roles"? He didn't even want to be a Feudal Overlord, ever and despised the mannerisms of the highborn, and now he suddenly will be the next lord and has a dresser forced on him without his consent, which is another thing - has a valet nothing else to do in a household?